For the dough, mix flour, baking powder, 100 g sugar, vanillin sugar and salt in a mixing bowl. Add milk, oil, 1 egg and 200 g quark and knead with the dough hooks of the hand mixer to a smooth dough. Roll out the dough on a greased fat pan of the oven (32 x 39 cm). Crumble the biscuits and spread them on the dough
Wash the lemon hot, grate dry and use a zest ripper to cut the peel into thin strips and chop. Halve the fruit and squeeze the juice. Mix 800 g quark, sour cream, 4 eggs, 175 g sugar, starch, lemon zests and 3 tbsp lemon juice. Fold in berries. Pour cream on the dough and spread
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 30-40 minutes. Remove from the oven and allow to cool on a cake rack