For the crumbles, coarsely grate marzipan. Put butter in flakes, marzipan, 125 g sugar, flour and egg yolk in a bowl. Knead into crumbles with the dough hooks of the hand mixer. Grease a springform pan (26 cm Ø) and dust with flour. Put about 2/3 of the crumbles on the bottom of the form and press it to a flat bottom. Sprinkle with breadcrumbs and chill.
Wash the plums, dab dry, halve and stone them. For the curd mixture, beat the eggs with the whisk of the hand mixer until thick and frothy. Add 175 g sugar and vanillin sugar. Stir the quark and mascarpone until smooth, stir in the egg cream. Sift the pudding powder on top and mix everything well. Pour a little quark mixture on the base and smooth it down. Spread about 2/3 of the plums on top. Pour the rest of the cheese mixture on top, smooth it down. Bake in the preheated oven (electric cooker 175 °C/ convection oven: not suitable/ gas: level 2) for 70-75 minutes on the lower shelf. After about 25 minutes baking time, spread the remaining crumbles and plums on the quark mixture. Cover the cake after about 1 hour if necessary.
Pour a little quark mixture on the base and smooth it down. Spread about 2/3 of the plums on top. Pour the rest of the cheese mixture on top, smooth it down. Bake in the preheated oven (electric cooker 175 °C/ convection oven: not suitable/ gas: level 2) for 70-75 minutes on the lower shelf. After about 25 minutes baking time, spread the remaining crumbles and plums on the quark mixture. Cover the cake after about 1 hour if necessary. Place the cake on a cake rack, remove from the edge of the springform pan and allow to cool in the pan. Whipped cream tastes good with it
waiting time approx. 3 hours