Prepare the pizza dough according to the instructions on the package and roll out on a greased baking sheet. For the topping, cut the onions into strips. Dice the bacon and leave it in a pan. Add onions, fry until translucent and season with pepper. In the meantime, whisk the creme fraiche with the 2 eggs and the 2 egg yolks, a pinch of salt, pepper and nutmeg. Spread the onion bacon mixture on the pizza dough. Pour the egg cream over it. Bake in the preheated oven on the lowest rack at 200 degrees for about 40 minutes.