Beat the butter until frothy. Then add eggs, sugar and vanilla sugar and stir well. Mix the flour and baking powder, sieve and stir in. Fold the apple slices into the batter. Spread the mixture on a greased baking sheet.
Bake in a preheated oven at 180 ° C for approx. 25-30 minutes (make a stick test!).
Tip: If you like, you can sprinkle icing sugar and lemon juice over the hot cake.