Finely chop the chocolate. Put ground hazelnuts, chocolate, eggs, 200 g sugar and baking powder in a bowl and mix with the whisk of the hand mixer for 3 minutes. Spread the mixture into a greased springform pan (26 cm Ø) sprinkled with flour. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 1 hour. Let the base cool down in the mould. For the filling, soak the gelatine in cold water.
Sort 250 g raspberries. Mix quark, 100 g sugar and lemon juice, add yoghurt. Squeeze the gelatine, dissolve lukewarm, stir into the quark. Cool until the cream begins to gel. Whip cream and vanilla sugar until stiff, fold in. Fold in prepared raspberries as well. Carefully cut the base once. Place the bottom cake layer on a plate and cover with the edge of the springform pan. Spread half of the cream on top. Place the second cake layer on top and spread the rest of the cream. Sort blueberries, currants and 100 g raspberries and sprinkle on the cream. Chill for about 1 hour.
Carefully cut the base once. Place the bottom cake layer on a plate and cover with the edge of the springform pan. Spread half of the cream on top. Place the second cake layer on top and spread the rest of the cream. Sort blueberries, currants and 100 g raspberries and sprinkle on the cream. Chill for about 1 hour. Roast the hazelnuts in a pan without fat until golden brown, take them out and let them cool down. Serve the cake sprinkled with roasted hazelnuts
waiting time approx. 2 hours