1. Start with the buttercream by making a pudding. Add the cornstarch and sugar to a small bowl and mix with some of the milk until the cornstarch has dissolved completely. Add the rest of the milk and vanilla extract to a small pot and bring to a boil (stir constantly). As soon as the milk starts to bubble, add the cornstarch mixture and mix in until the pudding starts to thicken. Take off the heat, cover with a piece of plastic wrap and let cool down completely. Make sure the plastic sits directly on the surface of the pudding so you don’t get a pudding skin.

 

2. Preheat the oven to 350°F (180°C). Line three 6 inches (15cm) springform tins with baking parchment and grease lightly. Set aside.

 

3. Add the eggs and brown sugar to a large bowl and mix until light and fluffy. Add the milk, cooled espresso, vegetable oil, and vanilla extract and mix until well combined. Mix the almond flour, cocoa powder, coconut flour, baking powder, baking soda, and salt in a separate bowl until combined. Add to the large bowl and mix until just combined. Divide the batter between the three baking tins and bake for 25-28 minutes or until a toothpick inserted into the center of the cakes comes out clean. Take out of the oven and let cool down on a wire rack for about 10 minutes, then remove from the tins and let cool down completely.

 

4. As soon as the pudding has cooled enough and the cakes are cooled, you can finish the buttercream. Add the softened butter and confectioners‘ sugar to a large bowl and mix on high speed until light and fluffy. Add the cooled pudding gradually with a spoon while mixing constantly until you get a nice and smooth buttercream.

 

5. To assemble the cake, palace the first cake layer on a serving plate, add some buttercream on top and spread evenly. Sprinkle with some rainbow sprinkles and place the second cake layer on top. Repeat with buttercream, sprinkles and then top with the third cake layer. Coat the cake with a thin layer of buttercream (crumb coat) and place in the fridge for about 20 minutes. Coat the cake with more buttercream – keep some for the decoration. Try to get a nice and smooth surface and edge.

 

6. Start with the m&m’s on the bottom of the cake and make one full round along the base of the cake. The next line should start a bit shifted to the right to get a diagonal line with each color. Go as high with the m&m’s as you like – it does not have to go all the way to the top. You can make a different pattern – just do what you think looks best ;) Decorate the top of the cake with the remaining buttercream – sprinkle with more m&m’s or sprinkles (optional). Keep in the fridge – the decoration tends to fall off if the cake is too warm.