Kolaches mean different things in different parts of the U.S.
In Chicago, they're often filled with sweet things, and sold by mom-and-pop shops and bakeries.
In Houston, they're mainly for breakfast, with things like eggs, bacon, sausage, brisket, etc. and sold by chains like Shipley's and Kolache Factory: https://kolachefactory.com
Recently, the Houston version of kolaches has made inroads into Chicago: https://www.howdykolache.com
https://en.m.wikipedia.org/wiki/Pączki
Paczki Day is almost as big a holiday in Chicago as Casimir Pulaski Day.
https://reluctantentertainer.com/buttermilk-pancake-pigs-in-...
https://www.texascooking.com/recipes/sausage-bundt-cake.htm
https://newfoundland.ws/christmas-old-time-pork-cake-recipe/
Referring to the Finnish variety or other ?