Chop 300 g chocolate. Melt with the butter over a warm water bath. Coarsely chop almonds and nuts. Whisk the eggs with a whisk. Mix flour and baking powder in a bowl.
Add sugar, vanillin sugar, salt, eggs and chocolate mixture. Mix everything briefly with the whisk of the hand mixer to a smooth dough. Fold in almonds and nuts. Grease a rectangular form (26 x 38 cm) and dust with flour. Fill in the dough and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 25-35 minutes. Let cool on a cake rack. Chop 100 g dark chocolate and white chocolate separately. Heat 100 g whipped cream and melt dark chocolate in it. Heat 75 g cream and melt white chocolate in it.
Let cool on a cake rack. Chop 100 g dark chocolate and white chocolate separately. Heat 100 g whipped cream and melt dark chocolate in it. Heat 75 g cream and melt white chocolate in it. Spread the icing alternately in blobs on the cake. If necessary, spread a little, let it set. Cut into pieces and decorate with almonds and nuts
2 1/2 hours waiting time