Roughly chop the walnuts. Coarsely chop 300 g chocolate and melt with butter in a hot water bath. Cooling
Beat the eggs, sugar, vanillin sugar and salt until fluffy. Mix flour and baking powder, sieve on top and fold in. Fold in melted chocolate and walnuts
Spread into a greased fat pan (approx. 32 x 39 cm) and bake in a preheated oven (electric cooker: 175 °C / convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Let them cool down
Break 200 g chocolate into pieces. Melt with cream and plate-fat while stirring at a mild heat. Leave to cool for about 15 minutes. Spread on the cake, sprinkle with pistachios and cut into quarters. Chill for about 2 hours. Cut into about 60 pieces (approx. 4 x 5 cm). Serve with vanilla ice cream and ready-made chocolate sauce