Knead a dough from 200g flour, 75g sugar, 1 packet of vanilla sugar, salt, baking powder, 1 egg and 100g pieces of fat and roll it out to fit the springform pan (26 cm). Put in a greased dish and pierce several times. Refrigerate.
Whisk the sour cream with sugar, sauce powder, vanilla sugar and 3 eggs.
Peel the apples and spread them roughly diced on the floor. Then pour the sour cream on top.
Use the remaining ingredients to make 150g flour, 75g sugar, cinnamon and 75g fat and spread them on the cake.
Bake at 175 ° C / fan oven for 45 - 50 minutes. After cooling, sprinkle with powdered sugar.