Mix espresso powder with 4 tablespoons of hot water. Cream fat with salt and 450 g sugar. Stir in eggs one after the other. Mix flour and baking powder, alternating with 150 g sour cream. Remove 1/3 of the dough, stir in espresso.
Grease the fat pan of the oven (32 x 39 cm) and dust with flour. Add light-coloured dough and smooth it down. Spread the dark dough in splotches on top. Spread the mocha beans on the dark dough and press in a little. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-35 minutes (test with sticks!) Let cool on a cake rack. Mix 125 g sugar with cream setting agent. Stir mascarpone and 500 g sour cream until smooth. Let the cream mixture trickle in. Spread on the cake and refrigerate for about 1 hour.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-35 minutes (test with sticks!) Let cool on a cake rack. Mix 125 g sugar with cream setting agent. Stir mascarpone and 500 g sour cream until smooth. Let the cream mixture trickle in. Spread on the cake and refrigerate for about 1 hour. Cut into pieces shortly before serving
2 hours waiting time