Melt the butter. Mix 100 g flour and 50 g sugar. Add the butter and work into crumbles using the dough hooks of the hand mixer. Chill the crumbles. Heat the jam and stir until smooth.
Mix quark, milk, oil, 75 g sugar, vanilla sugar, egg and salt with the whisks of the hand mixer. Add 300 g flour and baking powder and knead to a smooth dough with the dough hooks of the hand mixer. Divide the dough into 8 equal pieces. Form into flat cakes (8 cm Ø) with floured hands and place 4 flat cakes on a baking tray lined with baking paper. Spread the jam evenly on top. Wash and quarter the apples and remove the core. Cut quarters into slices and sprinkle with lemon juice. Spread apple slices on the flat cakes and cover with crumbles. Bake the baking trays one after the other in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes.
Wash and quarter the apples and remove the core. Cut quarters into slices and sprinkle with lemon juice. Spread apple slices on the flat cakes and cover with crumbles. Bake the baking trays one after the other in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes. Remove from the oven, place on a rack and allow to cool. Dust with icing sugar
30 minutes waiting time