For the coconut slices with currant jam, cream butter with powdered sugar and vanilla sugar. Slowly beat in the yolks one at a time. Mix flour with baking powder, and fold in with milk.
Spread the mixture on a greased and floured baking tray. Spread currant jam on top.
For the topping, whip egg whites and gradually add sugar. Fold in the coconut oil and spread evenly on the jam-coated dough.
Bake the coconut slices with currant jam at 175°C top and bottom heat for about 30 minutes.