For the currant cake, preheat oven to 180 degrees top and bottom heat.
Beat egg yolks with 150 g sugar and vanilla sugar until foamy.
Fold in melted butter. Mix the flour with the baking powder and fold into the mixture together with the milk and water.
Spread the dough on a baking tray lined with baking paper and bake in a hot oven for about 10 minutes until golden brown.
Let the oven cool down to 150 degrees Celsius. In the meantime, beat the egg whites with 150 g sugar until very stiff.
Fold the berries into the beaten egg whites and spread on the baked dough.
Bake in a 150 degree oven on the lowest rack just until the surface is lightly browned and dry.
After 20 minutes the currant cake is ready.