Separate 3 eggs. Cream soft fat, vanilla sugar and 150 g sugar. Gradually stir in 1 egg yolk and 3 eggs. Stir in sour cream, cream, starch, semolina and orange peel. Mix 2 egg yolks, milk, oil, quark, 100 g sugar and 1 pinch of salt. Mix flour and baking powder, add to the quark mixture and knead to a smooth dough with the dough hooks of the hand mixer.
Roll out the dough on a floured work surface to the size of the fat pan of the oven (38 x 34 cm). Grease the fat pan and put the dough in it. Beat the egg white with 1 pinch of salt until stiff, fold into the sourdough. Spread the sourdough on the dough and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 45 minutes, let cool off. Peel oranges so that the white skin is completely removed. Remove the fillets between the parting skins. Wash kumquats, cut into slices. Cut the cake into pieces. Spread orange fillets and kumquats on top. Mix the cake glaze with 20 g sugar in a small cooking pot.
Peel oranges so that the white skin is completely removed. Remove the fillets between the parting skins. Wash kumquats, cut into slices. Cut the cake into pieces. Spread orange fillets and kumquats on top. Mix the cake glaze with 20 g sugar in a small cooking pot. Gradually mix with 250 ml water, bring to the boil while stirring. Spread the icing with a tablespoon on the fruits, let it get firm
waiting time approx. 2 hours