Grease a fat pan (approx. 32x39 cm; at least 3.5 cm deep) and dust with flour. Coarsely chop the nuts. Break 300 g chocolate into pieces. Dice 250 g butter. Melt with the chocolate pieces in a hot water bath, let cool down lukewarm
Whisk the eggs briefly. Mix 350 g flour, baking powder, sugar, vanillin sugar and 1 pinch of salt. Add eggs and chocolate butter mixture, mix everything briefly with a hand mixer until smooth. Add the chopped nuts. Spread on the fat pan. Bake in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for about 20 minutes. Let them cool down
Break 200 g chocolate into pieces. Melt with cream while stirring at low heat, let it cool down for about 5 minutes, stirring more often. Spread on the cake. Decorate with almonds. Chill for about 2 hours. Serve with melted vanilla ice cream