Start by whisking the sugar, butter, eggs, lemon juice, and vanillin sugar together. Then slowly sift in the flour and baking soda. Add as much milk as needed to the mixture until it becomes a slow flowing dough. Part the dough into equal parts
Add 4-5 table spoons of cocoa powder to one part, and 2-3 table spoons of rum to the other part of the dough.
Fill both doughs into the same baking tin and swirl them up with a fork. Bake at 175°C for 1 hour.
VOILA 🧁 Guten Appetit