Mix 250 g butter with 250 g sugar and the vanilla sugar until frothy. Stir in the eggs one at a time. Add 400g flour and the baking powder alternately with the milk.
Place the dough on a greased baking sheet or drip pan.
Peel, quarter and cut the apples. Distribute evenly on the dough.
For the crumble, knead 120g butter, 120g sugar, cinnamon and 200g flour together to make crumbles and spread over the apples.
Bake in the preheated oven at 180 degrees for about 1 hour.