Peel, quarter and core apples and cut them into pieces. Wash and drain the raisins. Wash lemon hot, grate dry and finely grate peel. Halve lemon, squeeze juice. Heat lemon juice and vanillin sugar in a pot.
Add apples, cover and stew for about 5 minutes, mix in raisins and let cool.
Melt the butter and let it cool down. Separate eggs, chill egg whites. Mix flour with 1 pinch of salt, lemon rind and 200 g sugar in a bowl. Add egg yolk and butter, knead everything into crumbles with the dough hooks of the hand mixer.
Grease a springform pan (26 cm Ø). Put a good half of the crumbles in the mould and press them to a flat bottom, chill for about 30 minutes.
Beat the egg white until stiff, adding 50 g sugar and 1 pinch of salt. Stir the sour cream until smooth and fold in the egg white. Pour the mixture onto the crumble base and spread. Spread the apple mixture on top and crumble the crumbles over it.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 45-50 minutes. Let cool on a cake rack. Serve with vanilla ice cream and caramel sauce.