Clean, wash and stone the plums. Melt the fat, let it cool down. For the crumbles, knead 175 g flour, 75 g sugar, cinnamon, salt and fat first with the dough hooks of the hand mixer and then with your hands
Mix quark, milk, oil, 1 egg, 100 g sugar and orange peel. Mix 500 g flour and baking powder. Stir in one half of the flour, knead in the other half with the dough hooks of the hand mixer
Sour cream, 2 eggs, 75 g sugar and vanilla sugar. Roll out the dough on a greased, floured fat pan (approx. 32 x 39 cm). Cover with plums and pour over the sour cream. Spread crumbles on top
Bake in the preheated oven (electric cooker: 200 °C / convection oven: 175 °C/ gas: level 3) for 30-35 minutes. Let cool off. Whipped cream tastes good with it