Knead the dough ingredients on a low setting until crumbs form. Press 3/4 of the dough into a greased springform pan.
Drain the sour cream.
Mix the cornstarch with a little juice. Remainder Bring the juice to the boil, add the vanilla sugar and thicken with the starch. Bring to the boil briefly - then add the cherries and season with kirsch to taste.
Spread the cherry mixture on the floor and crumble the remaining dough over it.
Bake at 200 ° top and bottom heat for 25-35 minutes.