Mix the butter, sugar, vanilla sugar and egg yolks together until frothy, then add the flour mixed with the baking powder. Finally, beat the egg white until stiff and fold in. Spread the mixture on a greased baking sheet sprinkled with breadcrumbs.
Curd cheese mass:
Mix the butter, sugar, vanilla sugar and egg yolks together until frothy. Stir in lemon zest, lemon juice and curd cheese. Finally, beat the egg white until stiff and fold in. Now spread the curd mixture on the dough and cover with plums.
Streusel:
Melt butter. Stir in the flour mixed with pudding powder. Stir until crumbs are formed. Remove from heat, stir in the icing sugar mixed with cinnamon and spread the crumble on the cake.
Bake the cake in a hot oven at 180 ° C for about 45 minutes.