Butter burger

A butter burger is a hamburger topped with butter, either directly on the patty, or on the bun. Likely invented in Wisconsin, they remain popular in some northern parts of the midwestern United States, and are the principal item of Wisconsin-based fast food restaurant Culver's. Many restaurants in and around Wisconsin serve butter burgers.

History
In 1885, Charlie Nagreen served hamburgers fried in butter, at the Seymour fair, inventing the precursor to the butter burger in the process. The butter burger was popularized by the restaurants Solly's Grille and Krolls' beginning in 1936. Hamburger historian George Motz has posited that Solly's is one of what he called the last "real" butter burgers left, in that they use butter as a condiment and add up to three tablespoons of it on top of each hamburger.

Culver's, which was founded in 1984, butters the top bun, as opposed to the patty itself. In 2009, Steak 'n Shake introduced their "Wisconsin Buttery Steakburger", including Wisconsin butter and American cheese. In 2015, Jack in the Box introduced the "Classic Buttery Jack", a butter burger with garlic herb butter melted onto the patty.