1
Preheat the oven to 180°C. Whisk the eggs and sugar on high speed for 10 minutes. Sift the flour and cocoa over the egg mixture and fold in gently with a spatula. Spread the mixture evenly on an 18 cm diameter baking tray lined with baking paper (bottom) and bake for 15 minutes. Remove the baked sponge cake from the baking tray and cool on a wire rack.
2
While the sponge is cooling, prepare the moistening mixture and the creams (dark, milk and then white). Whip 450 g sweet cream and refrigerate (150 g for each cream). Melt the dark chocolate with 50 g cream over steam. Soak the gelatine in cold water for 5 minutes. Melt the strained gelatine in the warm chocolate and cool the chocolate until lukewarm. Using a spatula, stir in 150 g of whipped cream. Place the sponge cake on the base and place the ring on top. Moisten with cocoa and spread with cream. Smooth the topping and place in the fridge to firm up.
3
While the first layer of cream is cooling, use the same procedure to prepare the milk cream. Spread it evenly over the dark cream, flatten the surface and put it in the fridge to set. Prepare the white cream in the same way and put the cake in the fridge to stabilise the creams.
4
Remove the ring from the cooled cake and decorate as desired.