I already mentioned that I live in the northernmost Bundesland of Germany, Schleswig-Holstein: The land between two seas, between the Baltic Sea and the North Sea. Until 1864 the northern part Schleswig belonged to Denmark, where the writer and lyricist Theodor Storm was born. One of his favourite dishes were Förtchen, in Danish Æbleskiver. He liked the German version so much, that he wrote a nursery rhyme about Futtjes, low German for Förtchen.
You need a special pan to bake Förtchen. My grandmother had a pan with 7 indentations for a gas stove, my mother in law has a large pan for a coal-fired stove like this. Meanwhile you can buy pans with plain bottoms for electrical stoves. I borrowed this pan for baking Förtchen
There are different batters for Förtchen in all regions of Schleswig-Holstein. This cookbook from 1920 has 5 different recipes for Förtchen. The book recommends a mixture of lard and butter. My grandmother always baked them with yeast and raisins, so did I.
The Förtchen are done if they look inside like this.
Link to the Æbleskiver recipe in German language