Make a shortcrust pastry from the kneading dough ingredients.
Peel, quarter and slice the apples. Steam with the sugar, cinnamon and a little water for 5 minutes.
Mix egg yolks with sugar and vanilla sugar until frothy. Add lemon zest, quark and semolina. Beat egg whites until stiff and fold in carefully.
Butter a springform pan and line with about 3/4 of the dough. Place the apples on top, then pour the curd mixture over it. Crumble the rest of the dough over it. Bake at 180 degrees for 1 hour.