Mix the sugar, oil, vanilla soy drink, vinegar and rum flavor in a bowl.
Mix the flour and baking powder in another bowl, then fold into the liquid ingredients with a whisk until no lumps can be seen.
Pour half of the batter into a medium to small pan. Stir in 3 tablespoons of cocoa and 3 tablespoons of vanilla soy drink under the other half of the dough, then pour onto the light batter.
Bake in the non-preheated oven at 175 ° C top / bottom heat on the 2nd rack from the bottom for approx. 35 minutes. Use a wooden stick to test whether the cake is done, i.e. no more dough sticks.
Let cool, turn over. Melt the dark chocolate and cover the cake with it.
Tip:
You can also make a zebra cake this way, alternating thin layers of dark and light dough in the mold.