This recipe makes one layer: Melt butter and chocolate together in a pot over low heat. Whisk eggs and sugar until light and fluffy. Pour the chocolate mixture into the egg mixture. Sift flour, baking powder, salt, and cocoa powder into the bowl and fold the batter together. Pour into a greased springform pan and bake for 25 minutes at 175 degrees Celsius (347 degrees Fahrenheit). Take the cake out and let it cool.  

The same procedure applies to all three mousses: Soak gelatin in cold water. Chop the chocolate finely and melt it together with the cream in a pot over low heat. When the chocolate is completely melted and the mixture is smooth, wring the gelatin free from water and stir it into the warm mixture. Pour the mixture into a bowl and refrigerate for about 3 hours. Afterwards, the mixture can be whipped into a light mousse.  

Place one layer on a platter. Put the three mousses in pastry bags with star nozzles and "dab" them onto the layer. Place the second layer on top, and "dab" the three mousses onto it as well. Top with a bit of finely chopped dark chocolate. If you wish, you can melt 200g dark chocolate in the microwave and spread it around the edge of the layers... serve and enjoy ?