Pour mandarin oranges into a sieve and drain very well. Pour the sour cream into a mixing bowl. Wash the beaker and dry well. Beat the eggs, vanilla sugar and sugar with the whisk of the hand mixer until thick and creamy. Add bionade, oil and sour cream and stir in
Mix flour and baking powder and stir in portions. Dab mandarin oranges dry with kitchen paper and carefully fold into the dough. Pour into a greased, flour-scattered box form (2 3/4 litre capacity, 30 cm long, 13 cm wide, 8.5 cm deep, from Kaiser)
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 70 minutes. Cover the cake with aluminium foil after about 50 minutes of baking time. At the end of the baking time, take the cake out of the oven, place it on a cake rack, remove it from the oven and place it on the cake rack.
Remove the cooled cake from the mould, dust with icing sugar
waiting time approx. 3 hours