Process flour, baking powder, butter or margarine, sugar, salt and eggs into a shortcrust pastry and refrigerate. Roll out on a greased baking sheet dusted with a little flour. For the topping, mix the quark, pudding powder, egg yolks, sugar and salt and spread on the base. Place the sour cherries (if fresh: pitted) or drained from the glass on top. For the crumble, quickly process the flour, butter, sugar, salt, vanilla sugar and cinnamon into crumbles and distribute evenly on the cake and cook in the preheated oven on the second rack from the bottom with top / bottom heat to 180-190 ° for approx. 35-45 minutes . to bake. Let cool and dust with icing sugar.