Wash the orange hot, rub dry and rub half of the peel thinly. Knead 75 g sugar, 150 g flour, orange zest and 80 g butter first with the dough hooks of the hand mixer, then with your hands to crumbles. Keep cold. Cream 175 g fat, vanilla sugar and 175 g sugar with the whisks of the hand mixer. Stir in the eggs one by one. Mix 275 g flour and baking powder and stir in alternately with the egg liqueur. Fill the dough into a greased and flour-spreaded springform pan (26 cm Ø).
Press half of the blueberries into the cake, sprinkle the other half on top. Spread crumbles on the blueberries. Bake the cake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 45-55 minutes (stick test). Take the cake out of 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