Beat the sugar, butter (or margarine), vanilla sugar and eggs until frothy. Add the flour, half of the baking powder and cornstarch, stir until smooth and add a splash of lemon juice. (I recently just stirred a little bit of grated chocolate into the dough, it tastes really delicious, especially in combination with the sour cherries).
Put the dough in a greased round baking pan. Finally, put the cherries on the dough and distribute them nicely.
Bake at approx. 160 degrees (depending on the oven) for 40 - 50 minutes. I always do the stick test.
Let the cake cool and sprinkle with powdered sugar.
Another little tip: try the cake with peaches (I take the cake peaches out of the tin, they are nicely cut) instead of the cherries.