For the crumbles, place flour, 225 g sugar, 2 packets of vanillin sugar, salt, nuts, cinnamon and butter in flakes in a mixing bowl and knead with the dough hooks of the hand mixer. Then work into crumbles with floured hands
Place about 2/3 of the dough in a well-greased, flour-spread fat pan and press it down with your hands to a smooth base. Peel 3 oranges so that the white skin is completely removed. Using a sharp knife, remove the orange fillets between the parting skins and cut in half. Wash 1 orange, rub dry and rub the peel. Halve the orange, squeeze the juice. Mix quark, cream cheese, 225 g sugar, pudding powder, orange juice and zest and eggs and carefully stir in orange filets
Pour on the curd mixture and smooth it down, spread the remaining crumbles on top. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 1 hour. Take out and let cool down. Tastes best when left to rest overnight. Cut the cake into pieces and remove from the fat pan and dust with icing sugar as desired