Finely grate the marzipan. Knead 75 g sugar, 150 g flour, marzipan and 80 g fat first with the dough hooks of the hand mixer, then with your hands to form crumbles. Chill for about 30 minutes. Sort blueberries, wash and dry on kitchen paper. Cream 175 g fat, vanilla sugar and 175 g sugar with the whisk of the hand mixer. Stir in the eggs one by one. Mix 275 g flour and baking powder and stir in alternately with buttermilk.
Fill the dough into a greased and flour-spreaded springform pan (26 cm Ø). Sprinkle blueberries on top. Spread crumbles on the blueberries. Bake the cake in the preheated oven (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for 50-60 minutes (stick test). Remove the cake from the oven, remove from the edge of the springform pan and let it cool down on a cake rack. Dust with icing sugar before serving. Whipped cream tastes good with it
Waiting time approx. 1 hour