Preheat the oven. Mix the eggs with the sugar to a frothy mixture. Stir in margarine/ butter and 1 packet of vanilla sugar. Mix the flour with the baking powder and stir into the milk. Spread the dough into a greased cake tin. Prick the base several times with a fork and pre-bake for 10 minutes.
Currently separating the eggs. Beat 8 egg whites until stiff. Cream sugar and 7 egg yolks. Add the ingredients in the indicated order one after the other and stir in, finally adding the cheesecake aid/ custard powder. Spread the mixture on the cake base.
Spread the cheesecake mixture with a whisked egg yolk.
Baking: Bake in a preheated oven (convection oven) at 150-160 °C for approx. 70 minutes TIP: Remove the cheesecake after 35 minutes. Cut along the inner edge of the springform pan with a knife. Let the cake stand for 5 minutes and then bake for about 35 minutes more. This way the cake will not sink in after baking.