Roughly chop the chocolate. Melt butter and chocolate in a small pot at low heat while stirring. Remove from the stove. Whisk the eggs. Roughly chop the nuts.
Put melted butter and chocolate in a large mixing bowl. Add sugar, vanilla sugar, salt, eggs, nuts, flour and baking powder. Mix with the whisks of the hand mixer to a smooth dough. Grease the fat pan of the oven well. Spread the dough evenly over it. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Remove from the oven and let it cool down on a cake rack. In the meantime, chop the chocolate coating coarsely for the icing. Stir cream, couverture and coconut oil in a small pot at low heat until a creamy mixture is formed. Remove from the heat, allow to cool for about 15 minutes and then spread evenly on the cake.
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Remove from the oven and let it cool down on a cake rack. In the meantime, chop the chocolate coating coarsely for the icing. Stir cream, couverture and coconut oil in a small pot at low heat until a creamy mixture is formed. Remove from the heat, allow to cool for about 15 minutes and then spread evenly on the cake. Put the cake in a cool place for 1 1/2-2 hours. Then cut into 60 pieces
waiting time approx. 2 1/2 hours