Mix the flour, yoghurt, oil, eggs, sugar, vanilla and baking powder into a smooth dough and pour it into a 26 cm springform pan.
Mix the quark with yogurt, sugar, egg, vanilla pudding powder and lemon juice and pour onto the dough. Peel and core the apples and cut into cubes. Place the apple cubes on the quark-yoghurt mixture and press lightly. If necessary, sprinkle with 2 tablespoons of sugar and cinnamon. Bake at 180 degrees (convection) in a preheated oven for 35 minutes.