Cook a pudding from the milk, sugar and 2 p. Custard powder. Let cool and stir with the sour cream.
For the dough, beat the butter with sugar until frothy. Add egg. Mix flour with baking powder and stir in. Put the dough in a springform pan (28 cm), spread the pudding on top. Put the drained mandarins on the pudding and then bake everything at 160 ° - 170 ° for about 75 minutes.
After it has cooled down, prepare the icing, pour it on top and then ideally put it in the fridge overnight.