Zwiebelkuchen, which literally means onion cake in the German language, is either a one-crust pie made of steamed onions, diced bacon, cream, and caraway seed on a yeast dough or a leavened dough that is particularly popular in the German winegrowing regions mostly of Rhenish Hesse, the Palatinate, Franconia, and Swabia (a similar pie called Flammkuchen is also eaten in Alsace), or a quiche variant in Switzerland, traditionally eaten in Basel during the Carnival and in Bern for the Zibelemärit.