Wash oranges hot and rub dry. Grate the peel of 2 oranges. Cut 1 orange in half and squeeze it. Stir sour cream, sugar, vanillin sugar and cream cheese until smooth. Stir in eggs, semolina, sauce powder, orange peel and orange juice.
Grease a Savar form (28 cm Ø, 2.75 litres capacity). Grind one half of the biscuits finely in the universal chopper, crumble the other half coarsely. Mix both and sprinkle the mould thoroughly. Pour in the cheese mixture and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 55-65 minutes (test with sticks). Remove the cake from the oven and let it cool in the mould for 20-25 minutes on a cake rack. Turn out the cake onto a plate and let it cool down. Remove the zest from the remaining orange. Peel both oranges so that the white skin is completely removed. Cut the fruit flesh into thin slices and cover the cake all around with them.
Remove the cake from the oven and let it cool in the mould for 20-25 minutes on a cake rack. Turn out the cake onto a plate and let it cool down. Remove the zest from the remaining orange. Peel both oranges so that the white skin is completely removed. Cut the fruit flesh into thin slices and cover the cake all around with them. Sprinkle with orange zests and dust with icing sugar
2 hours waiting time