Mix the butter, sugar, flour, baking powder, vanilla sugar, egg yolks and milk and put the dough in a 26 cm springform pan. Place the chopped apples (the other fruit) on top of the batter.
Beat the egg whites into snow and stir in the sugar.
Put the snow on the apples and bake at 150 ° C for 45 minutes. Then let it stand in the switched-off oven for approx. 8 minutes.