Beat the eggs, put them in a bowl with the sugar and vanilla sugar and stir well. Add oil, yoghurt and eggnog. Mix the flour and baking powder and gradually stir in. Refine the dough with a little milk depending on its consistency. Stir very thoroughly until small air bubbles form. Now put the dough in a greased pan dusted with flour and bake at 150 degrees top / bottom heat for 60 - 80 minutes. Check after 60 minutes with a wooden stick and bake a little longer if necessary.