Drain the mandarins. Sort the blackberries, wash and drain. Cream fat, 175 grams of sugar and salt with the whisk of the hand mixer. Gradually add five eggs, add lemon zest.
Mix flour and baking powder and fold into the fat egg mass. Stir in milk. Put the dough into a greased fat pan of the oven and smooth it down. Add the mandarins and blackberries and bake in the preheated oven (electric range: 175 °C/ gas: level 2) for 45 minutes.
In the meantime, mix sour cream, remaining eggs, vanillin sugar and remaining sugar. After half the baking time, spread evenly on the cake and bake until the end. Remove the cake from the oven, let it cool down and serve dusted with icing sugar as desired.
Makes 24 pieces.