Mix 600 g butter in a food processor (bowl approx. 4 l capacity) until creamy. Gradually add sugar, vanilla sugar and 1 pinch of salt. Whip everything for about 10 minutes until thick and creamy.
Separate 10 eggs. Stir the egg yolks individually into the butter-sugar cream. Then stir in the remaining 5 eggs one after the other with approx. 50 g starch (by the spoonful) alternately. Stir in rum.
Sift 200 g starch, flour and baking powder. Stir into the butter-egg-cream in 2-3 portions. Beat the egg white in a very large bowl or in portions until stiff, adding 1 pinch of salt. Fold the beaten egg whites into the dough in 3-4 portions.
Preheat the oven grill. Grease the fat pan (deep baking tray; approx. 32 x 39 cm) and line with baking paper. Spread a thin layer of dough (approx. 6 tbsp.) with a tablespoon or pallet on the tray. Grill on the middle shelf for 1-2 minutes until the dough is light brown. Remove immediately.
Spread the next thin layer on the baked one, also grill over it. Process the rest of the dough in the same way (approx. 15 layers). Leave the cake to cool in the fat pan on a cake rack for about 1 hour. Loosen the edge with a knife, turn the cake onto a plate or board, remove the paper. Let it cool down.
Chop the chocolate coating and melt it with coconut oil in a hot water bath, let it cool down a little. Cut the dough sheet into 6 longitudinal strips (each approx. 5 cm wide). Cut each strip into 12 trapezoids (wide side approx. 4 cm, short side approx. 2 cm). Cover the tips with chocolate coating and let them drip off a little. Let dry on the cake rack.
It is easier to spread the first layer of dough on the baking tray if it is first heated under the hot grill for about 1 minute.
If air bubbles form on the dough during baking, prick them out with a wooden skewer.
To store the fresh Baumkuchen after cooling, wrap it in foil without decoration. It will keep in the refrigerator for 5-7 days.
If Baumkuchen is lying around for a few days, it will dry out a little. Then warm it up in the microwave for about 10 seconds on the highest setting. Tastes like freshly baked. Of course you can only do it without chocolate icing!
As a sweet souvenir, cut fir trees from a sheet of Baumkuchen. Cut the dough sheet into 4 longitudinal strips (each approx. 8 cm wide) and then cut each strip into approx.
Stick wooden handles into the trees. Melt 600 g chocolate coating and 2 cubes of coconut oil. Cover the trees, drain and decorate with sugar icing and pearls.