Grease a springform pan (26 cm Ø). Melt the butter. Mix flour, salt and 150 g sugar in a bowl. Mix in butter, halve crumble mixture. Fold nuts into one half and cocoa into the other half. Put the cocoa crumbles into the mould, press them to a flat bottom. Chill for about 30 minutes.
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 12 minutes. Remove and let cool on a cake rack. In the meantime, chop the chocolate and melt it over a warm water bath. Stir in nut nougat cream and 100 g sugar. Stir cream cheese until smooth. First stir in the chocolate mixture, then the eggs individually. Pour the cheese mixture onto the base and smooth it down. Spread nut crumbles on the cheese mixture. Bake in a hot oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 45-50 minutes.
Take the cake out of the oven and let it cool down on a cake rack. Remove the cake from the tin, dust with cocoa and cut into pieces.