Peel and core the apples and cut into thin slices. Drizzle with a little lemon juice and set aside. Grease a 26 springform pan. Knead a smooth shortcrust pastry from flour, butter, sugar, egg, salt and baking powder and place the pastry in the refrigerator for 30 minutes, wrapped in foil. Mix the quark, cream cheese, pudding powder and sugar until creamy, then stir in the eggs one after the other. Roll out the shortcrust pastry and line the springform pan with it, forming an approx. 3 cm high rim. Prick the bottom several times with a fork. Cover the base with the apple slices and distribute the cheese mixture evenly on top. Bake in the preheated oven at 180 ° for 45-55 minutes until the cheese has thickened. Let cool in the springform pan, then carefully loosen the edge.