Separate 3 eggs. Mix 100 g soft butter and 50 g sugar in a large mixing bowl with the whisks of the hand mixer until creamy. Stir in the egg yolks one by one. Mix 125 g flour and baking powder. Stir in flour mixture and milk briefly. Beat the egg whites until stiff, adding 1 teaspoon sugar and carefully fold in
Grease a square springform pan (24 x 24 cm) and dust with flour. Add the dough and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 12 minutes
Mix cream cheese, sour cream, 50 g sugar, 3 eggs, starch and caramel spread until smooth. Remove the cake, pour the cheese mixture on top and bake again at the same temperature for about 15 minutes
Knead 75 g butter, 50 g sugar, 175 g flour and 1 egg into crumbles. Peel apples and grate them to the core. Take the cake out of the oven again, spread grated apples on top and sprinkle with crumbles. Bake at the same temperature for about 20 minutes
Remove the cake and let it cool on a cake rack. Remove cake from the edge, dust with icing sugar and cut into pieces
Preparation time approx. 1 hour