Baked German Cheese Cake

(for a springform of 26 cm ). Stir the yeast with the milk and a half teasp of the sugar, put in a warm place for 15 minutes. For the dough, stir the rest of the sugar with the egg, salt, and the yeast milk. Add the butter and vanilla sugar. Sieve the flour over it and mix well. Knead ingredients for about 10 minutes, cover, and put in a warm place for about 45 minutes until about double the size. For the filling separate the eggs and put them into separate bowls. Beat the egg whites and 2 tablespoons of the sugar until stiff. Stir the egg yolks with the quark and the rest of the sugar. Stir the corn flour into the milk, add vanilla sugar and grated lemon peel. Stir cornstarch mixture into yolk-quark mixture, then carefully fold in the egg whites. Grease the form, pre-heat the oven to 220C. Knead the dough again, roll it out and put it into the form (you may push it up at the sides if you like). Spoon in the cheese mixture and bake for about 15 minutes. Reduce the temperature to 150C and bake another 45-50 minutes, until brown on top. When you take out the cake, it should have come up a good bit (like a mushroom cloud). It will level out (sink) and go a bit wrinkly on top when it cools down. Resist the temptation to taste it when still warm. When cooled down, put it into the fridge instead, where it will keep very well for days.