Put the flour and baking powder in a bowl. Stir.
In a bowl, place the eggs, sugar and vanilla sugar.
Whisk well. You do not need to beat with a mixer.
Add the oil. Whisk.
While sifting, add the flour and baking powder.
Stir gently, making sure the mixture does not form lumps.
Prepare a baking pan measuring 20/30 cm.
Grease and flour it.
Pour the mixture into the pan.
Bake in a preheated oven at 170 degrees without a fan for about 40-45 minutes until dry.
Note - since I baked in a thick glazed ceramic pan, baking in it usually takes longer. If you bake in a thinner, the cake will be ready in a shorter time. Monitor and check the readiness of the cake with a toothpick or wooden skewer.
While the cake is baking, prepare the topping.
Keep in mind that both the cake and the topping should be quite warm.
Put all the topping ingredients in the casserole.
Heat the mixture over medium heat and stir until the butter melts and the cocoa is absorbed by the liquid. It is not necessary to cook for a long time on the stove. You should get a homogeneous and shiny mixture.
After you take the cake out of the oven, let it take a breath for 4-5 minutes;)
Then pierce it with a knife over the entire surface to its bottom.
Using a spoon, carefully pour the topping over the cake.
Try to distribute the mixture evenly over the entire surface of the cake.
The cake absorbs the entire topping without any problem.
Let it cool before serving.
You can sprinkle with grated chocolate, coconut shavings, nuts or anything else you wish.