Beat the butter until smooth. Gradually stir in the sugar, salt and vanilla sugar. Then add the egg and finally the flour and baking powder.
Spread the dough in a greased and battered springform pan. Put the currants on top.
Bake in a preheated oven at 175 degrees top / bottom heat for about 25 minutes
In the meantime, beat the 2 egg whites with the sugar until stiff. After 25 minutes, spread the meringue on the berries. Then bake for about 8 minutes at 200-225 degrees.