Make a shortcrust pastry from flour, sugar, vanilla sugar, egg, baking powder and butter and chill for about 15 minutes.
Roll out the dough and place in a greased pie or tart pan (30 cm).
Mix the remaining ingredients with the whisk to a mixture, this is very liquid. Pour the quark mixture onto the dough and bake in the 180 degree preheated oven for about 70 minutes.
Keeps fresh for a few days.
Variation: The dough can be prepared with 1 tablespoon cocoa powder.