Haven’t tried them but Scuttlebutt’s in Lake Geneva has them on the menu as well as other Swedish specialties. I have always gone there for lunch and usually have a burger. They are across the street from the public beach and pier. Seems to me there is also a place in Rockford but can’t remember where or the name.

Scuttlebutt’s
831 Wrigley Drive
Lake Geneva Wisconsin
262-248-1111