Mix the flour, 120g sugar, margarine, egg, vanilla sugar, baking powder and lemon zest together and knead into a smooth dough. Line the bottom and the edge of a springform pan with it.
Bring the milk with the custard powder and 200 g sugar to the boil, allow to cool a little.
Mix the sour cream with the quark and then stir in the pudding mixture. Finally fold in the drained mandarins.
Pour the mixture into the mold and put it in the oven preheated to 180 ° C. Bake for about 1 hour.