Beat yolks with water, add sugar, vanilla sugar. Whip the egg whites and add them to the egg yolk. Add the flour with baking powder. Bake 25 minutes at 180 degrees. Cut the cooled cake in half. Prepare the filling. Cut strawberries and mix them with whipped cream. Save some cream and strawberries for decoration.
The two halves of the cake spread with milk, which optionally add a little rum. Then add the strawberry cream, cake cover with the other half of the dough.
At the end spread the cake with the cream and decorate it.