Mix the eggs with the sugar and vanilla sugar until frothy (if you don`t like it too sweet, you can only use half as much sugar). Then gradually add the other ingredients until a fluffy dough is formed.
It doesn’t matter whether you use a ring or a loaf pan, you should definitely grease the molds or line them with baking paper, otherwise the cake will stick.
Preheat the oven to 160 degrees and bake the cake for about 50 minutes.
Let it cool down well and, if you like, coat it with dark chocolate couverture, you don`t have to, because it is already very tasty.
By the way, I use small, normal coffee cups, not mugs.