Wash untreated orange hot, rub dry, finely grate the peel. Peel all oranges so that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins. Press the juice out of the parting skins, put aside
Cream butter, 175 g sugar and 175 g yoghurt with the whisk of the hand mixer. Stir in the eggs one after the other. Mix flour, baking powder and orange peel, stir into the dough. Spread half of the dough on the greased, floured fat pan of the oven (32 x 39 cm). Stir cocoa, 1 tbsp. milk and gingerbread spice into the other half and spread on the light-coloured dough. Spread the orange fillets on the cake
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 25 minutes. Take out the cake and let it cool down
Place 300 ml milk and 300 g yoghurt in a bowl, add cream powder and whisk for approx. 3 minutes until creamy. Spread the vanilla cream on the cake and let it set in a cool place for about 1 hour
Fill up the squeezed orange juice to 500 ml with orange juice. Mix the cake glaze powder and 4 level tablespoons of sugar in the pot. Gradually mix with the juice and bring to the boil while stirring. Immediately spread on the cake, let it set. Cut the cake into pieces and decorate with orange slices cut in half and orange peel as desired
Waiting time approx. 1 hour