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Chocolate Brownie Mousse Cake

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Each slice of this Chocolate Brownie Mousse Cake is absolute heaven! It’s a two layered cake that starts with a rich and decadent brownie. Then you have a high, lighter than air chocolate mousse that melts in your mouth.

Double Chocolate Brownie Mousse Cake - front on shot showing airy interior of mousse cake with slice taken out.

This cake isn’t for the faint of heart, it’s decadent! My perfectly light double chocolate mousse cake starts off with a chocolate brownie base that is topped with the lightest and most splendid mousse you’ve ever had. Slicing into this cake is so satisfying, eating it is simply divine!

Double Chocolate Brownie Mousse Cake - side by side image

Every wondered what eating chocolate air is like? This mousse is the answer! It’s got eggs that are perfectly whipped, paired with whipped cream and chocolate, it all comes together to create a lighter than air mousse. It’s not as airy as most other mouses, but it’s rich, perfectly set and each slice melts in your mouth.

Double Chocolate Brownie Mousse Cake - close up shot of slice of cake

If you’re as obsessed with chocolate desserts as I am, I have loads of recipes on the blog but my top recommendations are my Classic Chocolate Mousse, Fudgy Chocolate Brownie Pie and my Easy Chocolate Fudge Cake. All great chocolate desserts. I’ll leave a longer list at the bottom of this post!

Dreamy Chocolate Mousse in Cake Form!

I love this multi layered chocolate cake because it combines two of my favorite things. Creamy Mousse on top of a deliciously rich and fudgy brownie layer. Here’s some reasons you’ll love it!

  • Light and smooth – although not as airy as most other mousse cakes, the mousse layer is ultra light and silky in every bite!
  • Fudgy Brownie Layer – rich, buttery and chewy. Such a great contrast in texture to the mousse.
  • Ultra-chocolate hit – this recipe uses cocoa powder and melted chocolate with a little hint of coffee to intensify the rich chocolate flavor found throughout the dessert.

Double Chocolate Brownie Mousse Cake - slice of cake being held up on a spatula

Why this recipe works

A combination of gelatin and chocolate helps set this cake. It’s what helps give the mousse enough structure to stand on it’s own. The whipped eggs (gently cooked and safe to eat) combined with the whipped cream help make it light and airy!

Ingredients You Need To Make Double Chocolate Mousse Cake

Note: the whole recipe, including the ingredient quantities, can be found at the bottom of this page – just scroll down to the bottom, or click the ‘Jump to Recipe’ button at the top of this post.

Double Chocolate Brownie Mousse Cake - ingredients image 01

Brownie Layer

  • Butter – I used unsalted butter.
  • Cooking chocolate – make sure you use dark cooking chocolate. This can be found in the baking isle.
  • All-purpose flour – also known as plain flour.
  • Cocoa powder – use Dutch processed if you can because it has a stronger chocolate flavor and is less acidic. Natural will also work.
  • Salt – I used fine salt.
  • Eggs – I used large eggs.
  • Caster sugar – also known as superfine sugar. Granulated sugar will also work.
  • Brown sugar – light or dark will work.
  • Vanilla ExtractAlways use good quality vanilla extract when baking, it makes a huge difference. I have a great recipe here for it if you’d like to try your own!
  • Coffee shot – You can use a coffee machine to do this or just combine 2 tsp instant coffee powder with 1 tbsp boiling water.

Double Chocolate Brownie Mousse Cake - ingredients image 02

Chocolate Mousse Layer

  • Cooking Chocolate – I used dark cooking chocolate. Specifically, the Nestle cooking buttons which are designed to be easily melted and used for baking and desserts. They can be found in the baking isle of your supermarket.
  • Eggs – I used large eggs. For this recipe you’ll need to separate your eggs. It’s easier to separate your eggs if they’re cold. I’ve updated the recipe method to gently cook the eggs which makes them safe to eat.
  • Gelatin leaves – the gelatin leaves help the mousse set. There are different types of gelatin and different strengths. I used gelatin leaves which need to be soaked in water before being added to something warm to melt. In this case, the warm ganache for the mousse mixture. Strength wise: you’ll need a platinum strength gelatin. You can use gelatin powder instead. Simply mix 3 tbsp of gelatin powder with 6 tbsp cold water. Mix using a fork and allow to rest for 5 minutes. This is what you’ll add to your chocolate mixture and stir through until completely melted.
  • Vanilla Extract – same as above.
  • Caster sugar – also known as superfine sugar. Caster sugar is ideal for the mousse portion of the recipe as it melts into the meringue more easily than granulated sugar, reducing the risk of overwhipping and getting grainy mousse.

How to make Double Chocolate Mousse Cake!

For the full steps, check out the recipe card at the bottom of this post.

Double Chocolate Brownie Mousse Cake - steps 01

Brownie layer

  1. Melt the butter and chocolate over a double boiler.
  2. Combine the dry ingredients together.
  3. Whip the eggs and sugar together.
  4. Add the coffee shot (optional)
  5. Mix in the cooled chocolate and butter mixture.
  6. Add the dry ingredients and fold through.
  7. Pour into a greased and lined springform pan and bake.

Double Chocolate Brownie Mousse Cake - stpes 02

Mousse Layer

  1. Once baked, allow the brownie layer to cool completely, take out of the springform pan and line the side of the pan with acetate. More on acetate and where to buy it below.
  2. Soak the gelatin leaves (more on what to use instead of leaves below!)
  3. Melt the chocolate over a double boiler
  4. Mix soaked gelatin into the warm chocolate. Add the egg yolks and mix. Allow to cool.
  5. In a separate bowl, mix the egg whites and sugar and then stir over a double boiler until the sugar is melted.
  6. Allow to cool slightly before whipping until thick and glossy.

Double Chocolate Brownie Mousse Cake - steps 03

  1. Whip the heavy cream until you reach stiff peaks.
  2. Fold the meringue through the cooled (very slightly warm is ok) chocolate mixture and then fold through the cream.
  3. Add to the prepared tin.
  4. Allow to set in the fridge for 4 hours, ideally overnight before unclasping and peeling acetate away.

Double Chocolate Brownie Mousse Cake - a slice of cake sitting neatly on a plate

What happens if I don’t have Gelatin leaves?

Double Chocolate Brownie Mousse Cake - hand holding softened gelatin

Gelatin is one of the key things that helps this mousse set. If you don’t have them in leaf form, use gelatin powder. To use gelatin powder, simply mix 3 tbsp of gelatin powder with 6 tbsp cold water. Mix using a fork and allow to rest for 5 minutes. This is what you’ll add to your chocolate mixture and stir through until completely melted.

What if I don’t have acetate?

Double Chocolate Brownie Mousse Cake - acetate around cake.

I used acetate to help make taking this cake out of the springform pan easier. I bought mine on Amazon. If you search for food grade acetate it will come up. Anything about 4 inches in height is ideal. If you don’t have acetate, you can make this without it! Simply pour the mousse into the springform pan, let it set and then before unclasping it, dip a towel in hot water. Wrap the towel around the springform pan and allow it to warm the sides of the pan for 60 seconds. This will gently melt the mousse against the cake pan and help it slide out instead of sticking to the cake pan.

Tips and Tricks For Recipe Success!

  • Measure out using kitchen scales – measuring ingredients out by weight and not cups is the best way to get consistent results every time!
  • Make sure the chocolate is warm when adding the gelatin but cooled before adding the whipped ingredients. Don’t skip any of the steps!
  • Don’t skip any of the whipping! Whipping the egg whites and heavy cream are super important to helping this mousse get its air bubbles and light texture.
  • For a flawless slice – Before slicing into your cake, warm your knife up under some hot running water and then dry it. Do this with every slice for a restaurant quality flawless slice!
  • It’s really important that you allow adequate time to let this mousse set. I like letting it set overnight but you can give it a good 4-5 hours in a cold fridge before unclasping.

Double Chocolate Brownie Mousse Cake - wide shot of cake with slice taken out

Frequently Asked Questions about This Mousse Cake!

How do I store this?

This mousse cake can be made up to 2-3 days in advance. Simply store in an airtight container in the fridge. This cake can not be frozen.

Can this recipe be made gluten free?

Yes! There is flour in the brownies. You can replace the all-purpose flour (plain flour) with gluten free flour.

Can I leave the chocolate out?

Yes! The chocolate is in the brownie layer to help intensify the chocolate flavor but can be left out completely.

What is the best chocolate to use in the mousse layer?

Dark cooking chocolate. It’s designed to be easily melted and use in baking recipes. It can be found in the baking isle of your supermarket.

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Double Chocolate Brownie Mousse Cake - thumbnail image

Chocolate Brownie Mousse Cake

Each slice of this Chocolate Brownie Mousse Cake is heaven! It’s a lighter than air chocolate mousse layer sitting on top of a rich brownie layer.

Serves 8

4.5 from 35 votes
Print Recipe Pin Recipe
Prep: 30 minutes
Cook: 30 minutes
cool: 4 hours
Total: 5 hours
Course: Dessert
Cuisine: American
Calories: 930kcal

Ingredients

Brownie Layer

  • 1/3 cup (83 g) unsalted butter cut into cubes
  • 1/2 cup (100 g) dark cooking chocolate (see notes)
  • 1/2 cup (75 g) all-purpose flour
  • 2 tbsp (16 g) Dutch process cocoa powder sifted (see notes)
  • Pinch of salt
  • 2 large eggs room temperature
  • 1/3 cup (70 g) 70g caster sugar (superfine)
  • 1/3 cup (65 g) brown sugar
  • 1 tsp vanilla extract
  • 1 (20 ml) coffee shot

Chocolate Mousse Layer

  • 3 cups (630 g) dark cooking chocolate
  • 3 large eggs separated
  • 2 gelatin leaves platinum strength or above (see notes)
  • 1 3/4 cups (440 ml) heavy cream cold
  • 1 tsp vanilla extract
  • 1/4 cup (55 g) caster sugar

Learn How To Make it! [VIDEO]


Instructions

Brownie Layer

  • Preheat a fan forced oven to 160C/320F (170C/340F for no fan). Line the bottom of an 20cm / 8-inch springform pan. Set aside.
  • Add the chocolate and butter to a heatproof bowl and microwave for 30 seconds at a time, stirring each time until melted. Alternatively, you can do this using a double boiler. Set aside to cool slightly.
  • Add the flour, cocoa powder and salt to a small mixing bowl and use a whisk to combine.
  • To a large mixing bowl, add the eggs, both sugars and vanilla extract. Use an electric hand mixer to whisk until pale, fluffy and doubled in volume, about 2-3 minutes.
  • Add the coffee shot and mix until combined. Next, add the cooled chocolate mixture and whisk until well combined. Use a spatula to scrape the bowl down.
  • Add the dry ingredients and fold using the spatula until no dry ingredients are showing. Add the mixture to the springform pan and bake for 15 minutes. Once baked, allow to cool completely at room temperature. Carefully run a knife around the edge of the brownie to loosen from the springform pan. Clean the inside of the springform pan. Place a piece of baking paper on bottom and place the sides on top. Clip to tighten.
  • Spray the side of the pan with oil spray and place a large piece of acetate measuring 65cm (26-inches) in length on the inside. The oil will help it stick to the pan. Place the cooled brownie in the pan and set aside.

Mousse Layer

  • Chocolate - Add the dark chocolate and 3/4 cup (185ml) heavy cream to a heatproof bowl over a double boiler. Stir until melted. Take off the heat and add the egg yolks, mix using a spatula until combined. Keep the double boiler set up on the stove.
  • Add the gelatin leaves to cold water and allow to soak for 5 minutes. Once bloomed, take out of the water and squeeze excess water out. Add to the chocolate mixture and stir until gelatin is melted. Set aside to cool slightly.
  • Whipped Cream - Add the remaining 1 cup (250ml) of heavy cream and 1 tsp of vanilla extract to a medium sized mixing bowl and whip using an electric hand mixer until you reach stiff peaks. Set aside in the fridge until ready to use.
  • Swiss meringue - Add the egg whites and sugar to a large heatproof bowl and place on top of a double boiler. Whisk for 5 minutes or until the sugar has dissolved completely. You can test this by feeling it in between two fingers.
  • Take off the heat and allow to cool for 10 minutes. Use an electric hand mixer to whisk until the mixture doubles in size and becomes thick and glossy.
  • To complete the mousse, add half the meringue to the chocolate mixture and gently fold through using a spatula until well combined. Add the remaining meringue and the whipped cream and fold through until evenly combined.
  • Pour the mixture on top of the cooled brownie layer and spread around as evenly as you can. Chill in the fridge overnight. This needs a good amount of time to set properly.
  • To remove from the pan, run a knife under hot water and dry. Run it around the top of the mouse layer before loosening it from the springform pan. Carefully lift up the sides of the pan. Gently unwrap it from the acetate and slice to serve.

Notes

Gelatin - I used platinum strength gelatin leaves. You can use gelatin powder instead. Simply mix 3 tsp of gelatin powder with 6 tsp cold water. Mix using a fork and allow to rest for 5 minutes. This is what you’ll add to your chocolate mixture and stir through until completely melted.
Dark Cooking Chocolate - I used nestle cooking chocolate. Cooking chocolate is what you ant to use for this recipe as it’s designed to be used in baking recipes without seizing.
Dutch Processed Cocoa Powder - is an unsweetened cocoa powder which is lower in acidity and rich in chocolate flavor.
Acetate - can be bought at cake stores or online. I bought mine on Amazon. Search for ‘Cake Acetate’. You want one that is at least 5 inches in height.
Storage - Mousse Cake can be stored in an airtight container, in the fridge for up to three days.
Nutrition - is based on per slice. This makes 8 slices.
A note on measurements - all ingredients in this recipe are offered in Australian cup measurements and weight measurements. Australian cups are different to other cup measurements in different places in the world which means that no cup measurements anywhere are a reliable way to measure! Weight measurements are created by me, in my kitchen here in Melbourne Australia. The best way to get recipe success is to measure ingredients by weight, using kitchen scales.

Nutrition

Calories : 930kcal
Carbonhydrates: 69g
Protein: 14g
Fat: 74g
Saturated Fat: 44g
Polyunsaturated Fat: 3g
Monounsaturated Fat : 22g
Trans Fat : 0.3g
Cholesterol: 196mg
Sodium: 64mg
Potassium : 142mg
Fiber: 11g
Sugar : 46g
Vitamin A: 1164IU
Vitamin C: 0.3mg
Calcium: 64mg
Iron: 1mg
Nutrition Disclosure
Gave this recipe a go?Mention @thescranline or tag #thescranline!

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44 comments

Holly Wood July 27, 2021 - 5:50 am

Would it be ok to half the mousse recipe so it isn’t so tall, or would it affect the texture/setting of it? 🙂

Reply
Nick Makrides July 27, 2021 - 6:23 am

That would be ok 🙂 N x

Reply
Monique March January 23, 2022 - 9:06 pm

Hi Nick, could you use this mouse as a filling for between cake layers?? Sounds amazing 🥰

Reply
Nick Makrides September 10, 2022 - 12:42 am

Hi Monique! Sorry about the late reply. For this recipe, it wouldn’t be stable enough to hold the weight. Nx

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Claire Marina North August 27, 2021 - 3:11 am

5 stars
I like to bake alot and tried your recipie tonight. Unfortunately I could not find my 8inch springform pan so had to use a 9 inch and so the brownie was a little more thin than your recipie but it is delicious …and I am very finicky with baking. Your mousse is so light and it is a desert one would buy in a restaurant. thank you for this recipie

Reply
Nick Makrides September 19, 2021 - 2:57 am

That’s so lovely to hear Claire! I’m glad the recipe worked out and that you enjoyed it 🙂 N x

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Kirti Bhargava August 30, 2021 - 6:06 am

Since we are not cooking the eggs, isn’t it like having raw eggs?

Reply
Nick Makrides September 19, 2021 - 2:45 am

Hi Kirti! Yes. the eggs in this recipe are raw. In most countries (but not all) raw eggs are safe to eat. N x

Reply
Bella May 4, 2022 - 2:01 pm

No they’re not.. I don’t know who told you this but raw eggs can make peoooe very ill and you never mention even buying pasteurized eggs not that it matters. This recipe is full of animal cruelty based ingredients literally from the gelatin to the egg whites the yolks the cream literally all animal cruelty all the way through! no reason for any of it you don’t need gelatin you can use agar agar powder you don’t even need that cream you can use coconut cream or that silk brand whipping cream you can use coconut cream you can use other cream alternatives you don’t need eggs or egg whites you can use aquafaba you don’t need egg yolks either in any recipe for that matter! None any of those animal derived ingredients is needed. I’m not sure I understand why make a recipe with raw ingredients from an animal source that can make people sick when you can just swap it out for some thing that’s plant-based so people can eat it and not get sick? It’s really sad when you can avoid animal cruelty to make a really yummy recipe but it’s not avoided. I’ll never understand this way if thinking.

Reply
Nick Makrides May 5, 2022 - 7:39 am

Bella, other people exist in this world that have different views than you about ingredients or access to different ingredients that are safe to eat raw. I’m not going to sit here and try to change your mind because you have made your point and views crystal clear.

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Nick Makrides May 5, 2022 - 7:40 am

How funny, I don’t remember saying this recipe was vegan?

Reply
Jess May 5, 2022 - 7:18 pm

Hi bella, this is a non vegan recipe. If you want a vegan chocolate mousse recipe you should’ve gone on a vegan blog instead. If using animal products is cruel to you why did you come onto this website/blog in the first place. And also, in the UK and in Europe and Asia also, we use raw eggs all the time when making no baked desserts and even have semi cooked eggs, the way the food industry handles our eggs is safe. We also keep our eggs outside of the fridge. No harm to millions and millions of people. Please educate yourself, don’t wash your eggs until you need to actually use them that is only if there is physical dirt on them like a feather or something, because if you wash your eggs way before you eat them they will go bad faster, wash your hands after handling eggs if it gets messy, there you go no harm done.

Don’t put this wonderful food blogger down with your negative post. Thank you.

Reply
Nick Makrides May 6, 2022 - 3:47 am

Thankyou very much Jess. Very well written and 100% agree!

Vincent November 18, 2021 - 3:49 pm

Hi, Is there a specific type of gelatin sheet to use cause mine looks longer than yours?

Reply
Nick Makrides November 1, 2022 - 4:44 am

Hmm, I used the McKenzies Gelatin sheets. 3 of those sheets are equal to 1 tsp of gelatin. Hope that helps! N x

Reply
Kate December 2, 2021 - 2:22 pm

Hello – I have a question regarding the amount of chocolate. For ‘2 cups’ – is the the equivalent of 16 ounces, or one pound? Thank you!

Reply
Nick Makrides September 13, 2022 - 11:36 am

Hi Kate! Hmm, 2 cups of chocolate is equal to 400g. 🙂

Reply
Kate December 2, 2021 - 2:39 pm

Hi (again) – I had asked about the ounce equivalent for the ‘2 cups of chocolate’; but – I now see that you have the handy metric tab to convert the recipe. Thank you for that!! (you can ignore my earlier question)

Reply
Nick Makrides January 4, 2022 - 1:22 pm

Thanks Kate! N x

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Tara January 7, 2022 - 7:58 pm

Hi! When you say dark cooking chocolate do your mean unsweetened baking chocolate?

Reply
Nick Makrides September 10, 2022 - 1:02 am

Hi Tara! That’s right! N x

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Deanne January 20, 2022 - 10:32 pm

5 stars
I halved the recipe and made them in cupcake liners. My first time making mousse. Love it, thank you 🙂

Reply
Nick Makrides September 10, 2022 - 12:53 am

That’s amazing Deanne! Glad you loved the recipe! Nx

Reply
Miss November 15, 2022 - 8:30 pm

Hi Nick! Can you help me adapt this recipe to make it a dark chocolate mousse cake? My family likes dark chocolate. I could add coffee or rhum to intensify the flavor, but I certainly need to make changes to the type of chocolate used and the quantity of sugar. How would you adapt it to make it a dark chocolate mousse cake?

Reply
Nick Makrides November 26, 2022 - 6:36 am

I would swap the semi-sweet chocolate for 70% cooking chocolate. It’ll have a more dark/bitter flavour. I would not recommend making changes to the quantities of any of the ingredients N x

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Shari February 4, 2022 - 2:02 am

In step 2, do you add the ingredients in to the water? How much water?

Reply
Nick Makrides August 30, 2022 - 11:28 am

Nope, you add them into the bowl. N x

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Tamara Claxton February 8, 2022 - 6:08 am

If you don’t have acetate what can you use instead?.

Reply
Nick Makrides August 4, 2022 - 11:12 am

Hi Tamara, Hmm, I got this question yesterday. Unfortunately for this recipe, there isn’t an alternative. Sorry! N x

Reply
Carolina February 25, 2022 - 5:26 am

Your recipe looks amazing and I’m super excited to try it out but I cannot seem to find acetate anywhere? What is a good alternative for this? Cling wrap? Baking paper?

Reply
Nick Makrides August 2, 2022 - 10:32 am

Hi Carolina! I bought mine on amazon. Unfortunately, for this recipe I’m not sure there is an alternative. Acetate keeps it’s shape and doesn’t wrinkle.

Reply
Dana Messica April 7, 2022 - 10:02 pm

How many grams in a cup of chocolate in your recipe?

Reply
Nick Makrides April 27, 2022 - 12:51 am

In each cup of chocolate I get 200g chopped chocolate or chocolate chips.

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Susan Watt May 4, 2022 - 10:04 pm

5 stars
This cake really was heaven on a spoon

Reply
Tara March 26, 2023 - 5:05 am

Just wondering how long in advance could I possibly make this

Reply
Nick Makrides April 6, 2023 - 11:44 pm

Hmm, I’d say no more than 2 days. Hope that helps! N x

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Kathryn June 30, 2022 - 8:08 pm

3 stars
If you love chocolate you will love this but it is sooooooo rich. I never thought I would write that about chocolate. We won’t be eating any more only because it is way too rich for us. It was an easy recipe to make though and it turned out beautiful.

Reply
Nick Makrides August 1, 2022 - 5:36 am

Thanks so much Kathryn! N x

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Sarah March 2, 2023 - 2:24 pm

I haven’t made this yet so rating it would be daft, but doesn’t it look and sound fabulous! My question is: would this freeze well in a silicone cake mould to later cover in velvet lustre or mirror glaze – specifically the mousse?

Reply
Nick Makrides June 24, 2023 - 2:54 am

Hmm, I don’t think it would actually. Might be too soft to carry the weight of the glaze.

Reply
Amina jassat May 13, 2023 - 7:54 am

Hi I don’t have leave gelatine
Please can you advise me on
I do have powder gelatine
How much do I need to use for this recipe
And how much water
We’ve tried loads of receipes but none of them are light
Also being a Muslim we can’t eat the ones from the shops
I can’t wait to get started and make the most amazing chocolate mousse cake
I will give you the feedback
Off to the shops to do the shopping
Thank you in advance for the receipe

Reply
Nick Makrides June 24, 2023 - 3:18 am

Hi Amina! I understand and appreciate you can’t have gelatin. Totally get that. Unfortunately I haven’t tested this recipe using alternatives, so I couldn’t tell you how to make it using alternatives. However, if you do find a way to make it without gelatin and are happy with the results, please let me know and I’ll add a note to the blog post for anyone else who may be similar to you in their eating preference/beliefs. Nick xo

Reply
Jovy June 6, 2023 - 7:51 pm

5 stars
The cake is very, very decadent and sweet; a lil too sweet for my taste but perfect for anyone who loves that sort of thing, My mom definitely does and she requested something soft and creamy, so I found this recipe and made the cake for her birthday today. She absolutely loved it and so did all the guests.

P.s. for those wondering, I used gelatin powder (2tsp and 3tsp of water as instructed) and it turned out perfect.

Reply
Nick Makrides June 7, 2023 - 9:56 am

Thanks Jovy! N x

Reply

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