A Luther Burger, or doughnut burger (among several naming variations), is a hamburger or cheeseburger with one or more glazed doughnuts in place of the bun. These burgers have a disputed origin, and tend to run between approximately 800 and 1,500 calories (3,300 and 6,300 kJ).
I remember seeing on a food show years ago a burger with a doughnut as a bun. I’ve never tasted one but I thought to myself that might actually work.
https://en.wikipedia.org/wiki/Luther_Burger