Peel and halve apples and remove the cores. Cut the round surface of the apple halves several times with a knife. Beat the fat, sugar and vanilla sugar with the whisk of the hand mixer until foamy.
Stir in the eggs one by one. Mix flour and baking powder, add with the milk and mix everything to a smooth dough. Fill the dough into a greased springform pan (26 cm Ø), smooth it down and spread the apple halves on top.
Bake in the preheated oven (electric: 175 °C / gas: level 2) for 30-35 minutes. Pass the jam through a sieve and brush the cake with it about 15 minutes before the end of the baking time. Results in about 12 pieces.