Beat the butter with the eggs, sugar, salt and vanilla sugar in the food processor or with the mixer until frothy. Mix the flour, cornstarch and baking powder and mix into the mixture with 1/8 liter of milk. This is sand cake batter. Therefore, the whole cake will be nice and fluffy.
Approx. Remove 1 third of the dough. In it grated chocolate, cocoa, powdered sugar and 6 tablespoons. Mix the milk together.
Place parchment paper in a springform pan on the bottom. Grease the inner edges. Fat of your choice. First distribute the light-colored dough mixture on top. Pour the dark one over it and pull everything through the light dough while twisting with a fork.
Place the cake on the middle rail of the stove with a preheated 180 ° upper and lower temperature. Bake bottom heat for approx. 70 minutes. One has to check. Then take the cake out of the oven and let it cool down. Then dust with powdered sugar and remove the outer edge of the springform pan.
Cut pieces as required and add coffee. Good Appetite.