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Moist Chocolate Sheet Cake

This decadent Chocolate Sheet Cake has a rich chocolate flavor, covered in rich and creamy chocolate buttercream. It’s so easy to make and serve!

Chocolate Sheet Cake - slice coming out of the cake tin front on shot

By the way, if you’re looking for more decadence, check out my Chocolate Cupcake recipe, my Chocolate Brownies and my Chocolate Cheesecake!

Chocolate Sheet Cake - step by step

The taste sensation that is this ultra-rich and decadent chocolate sheet cake will send shivers down your spine. If this sounds like an experience you want to have, then you should make this recipe pronto! I have to say, the mere fact that this is incredibly easy to slice and serve just seals the deal for me. No layering or special decorating. Nothing fancy, just really good chocolate cake!

The Secret to Moist Chocolate Cake?

Boiling water! I know right? Wouldn’t that cook the batter? No. But it does incredibly wonderful things to your cake batter!

  • The cocoa burst! – it’s really hard to dissolve cocoa powder properly, but adding boiling water to your cake batter right at the end helps dissolve it which intensifies the chocolate flavor.
  • Homogony – love that word. The boiling water also creates a smoother more homogenous batter which leads to a softer and more tender more MOIST cake!

Chocolate Sheet Cake - slice being taken out shot from the side

This Cake is MOIST: Get over it.

I love how people are irked by that word, but look guys, we’re talking about cake here. It’s in keeping.

  • Moist and tender – this cake is so soft and tender but not crumbly or dense. It’s smooth, light, and chocolatey.
  • Easy to serve – this cake can be served in the tin it’s baked in. You bake it, frost it slice and serve!
  • Easy to make – this cake comes together quickly and easily. A few simple ingredients combined, and you have an easy to make cake! Plus, there’s no layering.
  • Rich Chocolate flavor – the intensity of the chocolate flavor is all consuming. It’s rich honey!

Let’s Talk About that Heavenly Frosting.

Honestly, it’s like a wave of decadence. I use two different types of chocolate in the frosting. It’s fluffy, smooth and creamy and perfectly pairs with this moist chocolate cake.

Chocolate Sheet Cake - hand spreading around frosting

Want some other indulgent frosting recipes that pair with this cake?

Ingredients You Need To Make Moist Chocolate Sheet 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.

Jump to Recipe

Chocolate Sheet Cake - ingredients image

Cake

  • Flour – I used all purpose flour.
  • Sugar – I used caster sugar which is also known as superfine sugar. It helps give you a finer crumb.
  • Natural Cocoa powder – natural cocoa powder is an acidic cocoa powder that reacts with the bicarb soda in this recipe and helps the cake rise.
  • Baking powder – helps the cake rise
  • Bicarb Soda – also known as baking soda reacts with the acidity in the natural cocoa powder which helps the cake rise.
  • Salt – I used fine salt.
  • Milk – I used cow’s milk but plant-based milk like oat, almond or soy will also work.
  • Coffee – this helps heighten the chocolate flavor. You can use a coffee shot from your coffee machine or just mix instant coffee powder with some boiling water.
  • Vegetable oil – you can use canola in its place.
  • Unsalted butter – let your butter cool a little before using.
  • Eggs – make sure your eggs are at room temperature.
  • Vanilla extract – use a good quality pure vanilla extract. I have a great one the site!
  • Boiling water – I go into this in more detail above, but the boiling water helps intensify the chocolate flavor and make the cake moister.
  • Chocolate sprinkles – optional but adds so much flair haha.

Frosting

  • Butter – I used unsalted butter. It’s SUPER important to make sure your butter is softened before using otherwise you won’t get creamy, fluffy frosting.
  • Salt – I used fine salt.
  • 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!
  • Powdered sugar – also known as icing sugar. Make sure you sift this!
  • Cocoa powder – It’s best to use a good quality Dutch process cocoa powder for this frosting. It has a deliciously strong flavor and is less acidic. Make sure you sift your cocoa powder!
  • Dark cooking chocolate – Using good quality chocolate is important in this recipe. I used semi-sweet chocolate with at least 70% cocoa. You can find cooking chocolate in the baking isle of your supermarket. Make sure you let your chocolate cool down before using in the frosting. Warm is ok, not hot.

How to make Moist Chocolate Sheet Cake!

Chocolate Sheet Cake - steps 01

  1. Combine dry ingredients in a bowl
  2. Combine wet ingredients in a separate bowl and add to dry ingredients
  3. Mix until no dry ingredients are showing
  4. Add boiling water last

Chocolate Sheet Cake - steps 02

  1. Mix until combined
  2. Line your 9×13-inch baking tray with baking paper
  3. Pour batter into the cake tin and bake. Allow to cool
  4. Add Chocolate Buttercream Frosting

Chocolate Sheet Cake - steps 03

  1. Spread around using a spatula or spoon
  2. Add sprinkles of choice
  3. Slice up and serve.

Chocolate Sheet Cake - front shot of cake sliced up into bars

My Top Chocolate Recipes!

While I have you here, here are some of my absolute favorite chocolate recipes that I think you would love!

Tips and Tricks For Recipe Success!

  • Use room temperature ingredients. Super important to get a homogenous batter that gives you a soft and tender cake.
  • Sift the dry ingredients to make sure there are no lumps, especially in the cocoa powder.
  • Use good quality ingredients – the butter and eggs make a huge difference!
  • Make sure your butter is softened for the frosting! It will make it creamier!
  • Let the cake cool before adding the frosting – seems obvious, but this was one of the first mistakes I ever made as a home baker 😂

For tips and tricks on making the Chocolate Buttercream Frosting recipe, click here.

Frequently Asked Questions about Moist Chocolate Sheet Cake

How do I store this?

This cake can be store in an airtight container for up to 5 days. If storing in the fridge make sure there’s no fridge smells because this cake will soak those up. Also thaw it before serving otherwise the frosting will be really stiff.

Can I lower the sugar in this cake?

Nope. That’s all. Nothing else to this answer. It’s a dessert, it’s sweet, eat a tiny piece haha.

How do I know when the cake is done baking?

If you enter a toothpick or skewer into the center of the cake and it comes out with dry crumbs but looks shiny on top, it’s perfectly baked. If it looks dry, it’s most likely overbaked.

Can I make this cake gluten free?

I haven’t tested this cake with gluten free flour, but I imagine it would work. If you give it a try,. Let me know how you went in the comments!

Can I leave the coffee out?

Yep! The coffee is in there to help heighten the chocolate flavor but

Gave this a go? Don’t forget to rate the recipe and leave a comment below! Hungry for more? Join me on Instagram, Facebook, Pinterest and TikTok for more great recipes!

Chocolate Sheet Cake - thumbnail 01

Moist Chocolate Sheet Cake

This decadent Chocolate Sheet Cake has a rich chocolate flavor, covered in rich and creamy chocolate buttercream. It’s so easy to make and serve!

Serves 20

5 from 4 votes
Print Recipe Pin Recipe
Prep: 10 minutes
Cook: 20 minutes
Cool: 2 hours
Total: 2 hours 30 minutes
Course: Dessert
Cuisine: American
Calories: 366kcal
Author: Nick Makrides

Ingredients

Chocolate Sheet Cake

  • 1 2/3 cups (250 g) all-purpose flour sieved
  • 1 3/4 cups (370) caster sugar
  • 2/3 cup (60 g) natural cocoa powder (see notes) sieved
  • 2 tsp baking powder
  • 2 tsp bicarb soda
  • 1 tsp salt
  • 1 cup (250 ml) milk
  • 1 coffee shot or 1 tsp instant coffee powder mixed with 2 tbsp boiling water.
  • 1/3 cup (80 ml) vegetable oil
  • 1/3 cup (80 g) unsalted butter melted
  • 2 large eggs
  • 2 tsp vanilla extract
  • 3/4 cup (185 ml) boiling water
  • 1/2 cup (80 g) chocolate sprinkles or rainbow sprinkles

Frosting

  • 1 1/2 cups (400 g) unsalted butter softened.
  • 1/4 tsp salt
  • 1-2 tsp vanilla extract
  • 1 cup (155 g) powdered sugar
  • 1/2 cup (50 g) cocoa powder sieved
  • 1 cup (200 g) dark cooking chocolate, melted and cooled to room temperature (see notes)


Instructions

Chocolate Sheet Cake

  • Preheat a fan forced oven to 160C / 320F. Spray a 33cm x 22cm / 13 x 9-inch baking dish which is 7cm / 2.5-inches in height with oil spray and line with baking paper. I used little metal clips to keep the baking paper in place.
  • Add the flour, sugar, cocoa powder, baking powder, bicarb soda and salt to a large mixing bowl and use a whisk to combine.
  • To a separate bowl add the milk, coffee shot, vegetable oil, melted butter, eggs and vanilla extract and whisk to combine.
  • Add the wet ingredients to the dry ingredients and whisk until no dry ingredients are showing. Scrape down the bowl to make sure no dry ingredients are hiding at the bottom or sides. Once combined, add the boiling water and whisk. The batter will thin out quite a bit which is normal.
  • Pour the batter into your prepare cake tin and place in the middle rack of your oven. Bake for 20 minutes. Once baked, allow to cool completely.

Chocolate Buttercream Frosting

  • Add your softened butter, salt and vanilla extract to a large bowl. If using a stand mixer fit it with the paddle attachment. Beat on high speed for 5 minutes until pale and fluffy.
  • Scrape down the bowl and add all the sifted powdered sugar and cocoa powder and begin beating on low speed. When no dry ingredients are showing, turn the speed up to high speed and beat for 10 minutes.
  • Scrape down the bowl again and add the melted chocolate. Beat on high speed until everything is well combined, about 5 minutes.

To Decorate!

  • Add the frosting on top of the cooled cake and spread around using an offset spatula or spoon. Finish with sprinkles. Slice up into 4 x 3 bars and serve.

Notes

Natural Cocoa Powder - this is a strong-tasting, high-quality cocoa powder with a naturally high acidity which reacts with the bicarb soda in the recipe and helps the cake rise.
Dark cooking chocolate - you want to use dark cooking chocolate and not regular eating chocolate for this recipe as it’s designed to be melted and used in baking recipes. Make sure you let the melted chocolate cool down before using. Warm is ok. Hot will melt your frosting.
Butter for frosting - Make sure your butter is soft! If you store your butter in the fridge, microwave it for 10 seconds at a time, flipping it over each time until it’s soft. Not melted. You want it to be soft enough that if you press on it with your finger there’s a little resistance, but your finger can make a dent.
Storage - Sheet Cake can be stored in an airtight container for up to 5 days. It get’s even more moist the next day!
Nutrition - is based on per slice/bar. This recipe serves 12.
A note on measurements - all ingredients in this recipe are offered in Australian cup measurements and weight measurements. 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 : 366kcal
Carbonhydrates: 27g
Protein: 4g
Fat: 24g
Saturated Fat: 15g
Polyunsaturated Fat: 1g
Monounsaturated Fat : 7g
Trans Fat : 1g
Cholesterol: 65mg
Sodium: 316mg
Potassium : 220mg
Fiber: 3g
Sugar : 13g
Vitamin A: 569IU
Calcium: 64mg
Iron: 2mg
Nutrition Disclosure
Gave this recipe a go?Mention @thescranline or tag #thescranline!

Chocolate Sheet Cake - front shot with bar taken out

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3 comments

Nick Makrides May 2, 2023 - 4:25 am

5 stars
There is nothing more moist to be honest! N x

Reply
Alison May 18, 2023 - 10:34 pm

Hi Nick. I’m really keen to try this recipe but I’m having trouble finding cocoa that isn’t Dutch processed. Could you please let me know which one you used here? Thanks heaps!!!

Reply
Nick Makrides June 24, 2023 - 3:10 am

Hi Alison, that’s ok, use the unsweetened cocoa powder you have on hand. Let me know how it goes and I’ll add notes to the recipe! N x

Reply

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