Käsekuchen - German Cheesecake - cooking recipe

Ingredients

For the Crust
1 1/2 cups all-purpose flour
1 teaspoon baking powder
1 pinch salt
2 teaspoons vanilla extract
2 teaspoons sugar
1 tablespoon finely grated lemon rind
1 egg, beaten
1/4 cup granulated sugar
7 tablespoons butter
For the Filling
3 egg yolks
3/4 cup granulated sugar
2 teaspoons vanilla extract
2 teaspoons sugar
7 tablespoons butter, very soft and at room temperature
6 ounces heavy cream
17 ounces Quark
1 1/2 tablespoons cornstarch
3 egg whites
1 pinch salt

Preparation

For the Crust:
Sift the flour, stir in the baking powder, salt, vanilla-sugar, lemon peel and sugar, then rub in the butter and knead to a smooth consistency with the egg. (Can use Food Processor).
Place dough in a plastic bag in the refrigerator for 1 hour.
Preheat oven to 300 degrees F.
You will need a 9 or 9 1/2-inch spring form pan.
Roll out the dough on a well-floured work surface.
Place dough in bottom of a 9 or 9 1/2-inch spring form pan, pressing it up the sides almost to the top. Set aside.
For the Filling:
Beat the egg yolks with the sugar and vanilla-sugar until pale and foamy. Add the softened butter and beat well, then add the heavy cream and beat again.
Add the quark and stir until the mixture is smooth and thoroughly combined.
Whisk the egg whites with the salt until very stiff, then very gently fold in the quark mixture, also adding the sifted cornstarch a little at a time.
Pour the filling into the crust shell and gently wobble the pan back and forth until the surface is smooth.
Trim the dough, leaving about 1 inch.
Bake in preheated 300 degrees F oven for 50 to 60 minutes (longer if necessary) until well risen and golden - it resembles a souffle at this point (It will sink in the middle quite dramatically - don't worry, it's supposed to do this).
Turn the oven off, and let the cheesecake rest in the oven for 15 minutes; then remove it from the oven, cool for an hour or so at room temperature, and refrigerate for several hours before releasing sides of pan and serving.