Preheat your oven to 175°C / 350°F. Spray a 12x17 inch baking tray with oil spray. Line the bottom with baking paper. Set aside.
Place a sieve over a medium mixing bowl and add the flour, baking powder and salt. Sift into the mixing bowl and set aside.
Add the egg whites to a separate medium mixing bowl and mix on medium speed using an electric hand mixer (or stand mixer fitted with a whisk attachment) for about 1 minute before slowing adding 70g - 1/3 cup of the caster sugar. Continue mixing until mixture becomes thick and glossy, about 3 minutes. Set aside.
Add the egg yolks, remaining sugar and vanilla bean paste to a large mixing bowl and whisk on high speed for 5 minutes until pale and fluffy. Add half of the egg white mixture to the egg yolk mixture and use a spatula to fold through gently until almost completely combined. Add the remaining egg white mixture and repeat.
Add the dry ingredients into the bowl.Gently fold through using a spatula until well combined. Lastly, drizzle the melted and cooled butter over the cake batter and fold through until you can see no streams of shiny butter. This batter is very light.
Add the batter to the prepare baking tray and use a spatula to gently spread the mixture as evenly as you can. Bake for10 minutes.
Take out of the oven and gently run a knife around the side of the tray to help loosen the cake. Dust with about 2 tbsp of powdered sugar. Place a large piece of baking paper over the cake followed by a large chopping board. Flip the cake over onto the chopping board and take the baking tray away. Peel the baking paper away from the bottom of the cake. Tightly roll the cake starting from the narrow end. You will have baking paper rolled up with the cake. This is going to help stop the cake from sticking onto itself as it cools. Allow to cool completely at room temperature.
Whipped Cream
Add the heavy cream and vanilla extract to a large mixing bowl. Use a mixer to whip to stiff peaks.
Assembly
Once the cake is chilled, carefully, and slowly unroll. Add the raspberry jam on top and use a spatula to spread around evenly. Then top with whipped cream and spread evenly leaving a 1-inch gap at one end of the cake. Roll up beginning at the end that has no gap. Wrap tightly in plastic wrap. Chill in the fridge for one hour.
Chocolate Glaze
Add the powdered sugar, cocoa powder, butter, and milk to a heat proof bowl. Microwave for 1 minute. Use a whisk to mix until well combined.
Let's Decorate!
Unwrap the cake from the plastic wrap and place on top of a cooling rack with a baking tray underneath. Pour the chocolate glaze on top and use a spatula or spoon to spread around. Finish by sprinkling with shredded coconut. Allow to set before slicing.
Video
Notes
StorageThis Lamington Swiss Roll can be stored in an airtight container for up to three days.