For the dough, mix the flour with baking powder, sugar and vanilla sugar in a bowl. Add the quark, oil and milk and work with the dough hook of the hand mixer to form a smooth dough. Roll out the dough, place it in the pan, press up one edge.
Peel, quarter and core the apples, cut into a fan shape and drizzle with a little lemon juice. Then spread the apples on the dough.
Preheat the oven to 175 degrees hot air.
For the topping, whisk the eggs with the cream and sugar and pour over the apples.