Peel, quarter, core and dice the apples. Put them in a pot with 250 ml apple juice and 1 packet of vanillin sugar, bring to the boil, cover and cook for about 5 minutes. Stir 1 sachet of custard powder with 50 ml apple juice until smooth. Pull the pot off the stove. Stir in the pudding powder. Let simmer for about 1 minute while stirring. Let it cool down, stirring again and again
Wash, halve and stone the plums. Put them in a pot with 250 ml apple juice, cinnamon stick and 1 tbsp sugar, bring to the boil. Cover and cook for about 5 minutes. Stir 1 sachet pudding powder with 50 ml apple juice until smooth. Pull the pot off the stove. Stir in the pudding powder. Let simmer for about 1 minute while stirring. Let it cool down, stir again and again, remove the cinnamon stick
For the crumbles, put flour, butter in flakes, brown sugar, salt, 1 packet of vanilla sugar and egg in a large mixing bowl. First use the dough hooks of the hand mixer, then work into crumbles with your hands. Spread a good 2/3 of the crumbles on a greased, floured baking tray (32 x 39 cm) and press them down to a smooth base with your hands. Spread the apple compote on one half of the base and the plum compote on the other half. Sprinkle the rest of the crumbles over it
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the lower rack for approx. 45 minutes. Let cool down a little. While still slightly warm, cut the cake in half to make an apple and a plum cake. Cut the apple cake on the tray into approx. 15 pieces. Let it cool down on the baking tray
Mix mascarpone and quark in a bowl until smooth. Mix 75 g sugar with cream setting agent. While stirring, let it trickle into the quark mixture. Put the plum cake on a board and spread with the cream. Place the apple pie cut into pieces on top. Chill for about 2 hours. Serve cut into pieces. Whipped cream tastes good with it
waiting time approx. 4 hours