Make a batter from butter, sugar, flour, eggs and baking powder. Pour the batter into a prepared springform pan.
Bake in a hot oven at 180 ° C top / bottom heat for approx. 15 - 20 minutes.
Cook the fruit juice with vanilla pudding according to the instructions on the packet. Fold in the fruit. Put the mixture on the pre-baked base and bake again in the hot oven for 15 minutes.
Beat egg whites until stiff. Mix the egg yolks and sour cream with the sugar, then fold in the egg whites. Spread this mixture back onto the pre-baked base. Return to the hot oven and bake for another 15 minutes.