It had never occurred to me that a kolache was more or less like a danish, but now that you mention it ... And that's really interesting about similar things being called Wienerbrød in Denmark, and Kopenhagener in northern Germany (so is that familiar to anyone, perchance?).
We don't actually have danishes much here in the south that I know of; I think of them as being more breadlike, without necessarily much filling but with more icing, and lower quality, more store-bought. But being a part of the country with a good deal of Czech heritage, we do have kolaches, which may indeed be somewhat similar.
A kolache (pronounced /ko'la:
tschi/) was a ubiquitous dessert on school lunch trays and is sometimes an alternative to a doughnut at group events. I don't really like them because they can be overly sweet -- as I recall, sweet dough with a sticky glaze, topped with a dollop of gooey jam-like filling in the middle, like a flattish jelly doughnut with the jelly on the outside. The doughnut-like glaze may have just been an aberration of our school cafeteria, though; the ones I see now look more like a yeast roll base. Apparently now in some places they also sell ones with ham, sausage, cheese, or cream cheese completely on the inside, but I'm not sure those are as authentic. Or rather, they may be authentic Czech, but not as authentic Tex-Czech. (-;
Some typical kolaches, more or less as I know them:http://www.kolachedepot.com/images/kolache.JPGhttp://4.bp.blogspot.com/_wC-K9A-4uOw/RnV3O2A...http://www.sxc.hu/pic/m/b/bl/blogless/560028_...
In contrast, what I think of when I think of danishes (maybe it's the crisscross icing):http://www.michelsbakery.com/images/pastries_...
(not the one in back, that's a scone or something else)
But it may be just that we don't use the word 'danish.' Actually, we might call them just sweet rolls (accent on 'sweet'), which is a more general term for sweet pastries.
I've never heard of a kolach/kolacs or seen any of those other spellings in English, and the kolaches I know are nothing like nut rolls or loaf shapes. I suspect that may need to be a separate entry, even if they undoubtedly share the same etymology somewhere along the way.