For the crumbles, mix flour and baking powder in a mixing bowl. Add 225 g sugar, vanillin sugar, salt, butter and egg yolk and mix with the kneading hooks of the hand mixer. Then work into crumbles with floured hands. Drain gooseberries well, put some aside for decoration. Put about 2/3 of the crumbles into a well greased springform pan (26 cm Ø).
Press into the mould to form a smooth base. Spread gooseberries on top, leaving a small rim free. For the sour cream mixture, mix 150 g sugar, 600 g sour cream, eggs and pudding powder with the whisk of the hand mixer. Pour the mixture carefully into the springform pan. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 60-65 minutes. Knead remaining crumbles with 70 g brittle. After 20 minutes baking time, spread the brittle crumbles on the sour cream mixture. Leave the cake to rest for 10 minutes in a switched-off oven. Carefully loosen the cake edge with a knife and let it cool down. Mix 100 g sour cream and 25 g sugar.
After 20 minutes baking time, spread the brittle crumbles on the sour cream mixture. Leave the cake to rest for 10 minutes in a switched-off oven. Carefully loosen the cake edge with a knife and let it cool down. Mix 100 g sour cream and 25 g sugar. Pour the mixture in biscuits onto the cake. Sprinkle cake with 30 g brittle. Place the remaining gooseberries on the sour cream
waiting time approx. 3 hours