For the coconut cake, beat the yolks, sugar, vanilla sugar, orange zest, coke oil and coconut milk until creamy. Gently stir in the flour sifted with baking powder and the coconut fat.
Fold in the beaten egg whites. Pour half of the mixture into a greased, rolled-out cake pan. Stir the cocoa powder mixed with rum or water into the other half of the dough.
Pour onto the light dough and carefully marbleize with a fork. Bake in the preheated oven at 180 degrees top and bottom heat for approx. 45 – 50 minutes. Test with a chopstick.
Remove from the mold and sprinkle with vanilla powdered sugar when cooled.