Roughly chop the plums. Put the plums and juice in a bowl and puree with a blender. Mix in the cranberries. For the crumbles, put flour, sugar, baking powder, salt, egg and butter in flakes into a very large mixing bowl and knead with the dough hooks of the hand mixer. Then work into crumbles with your hands
Put about 2/3 of the crumbles on a greased baking tray. Press down with your hands to a smooth base. Prick several times with a fork. Spread plums evenly with a knife. Knead oat flakes and cornflakes under the remaining crumbles
Spread the remaining crumbles evenly on the plums. Bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 50 minutes on the bottom shelf. Remove from the oven, place on a cake rack and allow to cool. Cut into pieces and arrange. Whipped cream tastes good with it
Preparation time approx. 1 hour 20 minutes