Melt the butter and let it cool down a bit. Wrap a sheet of parchment paper in the springform pan. Preheat oven to 350°F.
Beat the eggs in a mixing bowl for 1 min. until fluffy. Sprinkle in the sugar and vanilla sugar, and beat the mixture for a further 2 min. Mix the flour with the baking powder and cocoa and stir in briefly on the lowest level. Stir in the butter briefly. Spread the batter in the mold and place on the rack in the oven.
Baking time: about 35 minutes
Loosen and remove the edge of the springform pan. Turn out the cake onto a baking rack lined with baking paper and leave to cool.
Carefully peel off the baking paper. Turn back the base and cut horizontally three times. Place the bottom layer on a cake plate.
Whip the cream with the Whip It, then stir in the chocolate spread. Spread a third of the chocolate cream on the bottom layer. Lay on another base and press down lightly. Spread another third of the chocolate cream. Place the third layer on top and spread the remaining chocolate cream on top. Cover with the last layer. Put the cake in the fridge for at least 2 hours.
Place the couverture in a bowl. Boil the cream, pour over the couverture, leave to stand briefly and then mix with a whisk to a smooth mass. Let the icing cool down.
Pour the icing onto the cake, spread it out a little with a cake server or a palette and let it set in the fridge. Decorate the cake with chocolates before serving.