For the crumbles, put 300 g flour, vanillin sugar, 1 pinch of salt, 125 g sugar, egg yolk, 150 g fat in flakes and cinnamon in a mixing bowl. First use the dough hooks of the hand mixer, then work into crumbles with your hands.
Peel, quarter, core and cut apples into slices. Mix 250 g fat, 250 g sugar and 1 pinch of salt with the whisk of the hand mixer. Stir in the eggs one after the other. Mix 250 g flour, starch and baking powder and stir in.
Put the sponge mixture into the greased fat pan of the oven (32 x 39 cm) and smooth it down. Spread apple slices evenly on top, sprinkle with crumbles. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 40 minutes.
Remove from the oven, place on a cake rack and allow to cool. Serve with crème fraîche sprinkled with cinnamon.