I have been looking at recipes for galette bressane lately, it is made with brioche dough shaped into a flat circle with the center filled with butter, cream, whipped cream or creme fraiche, usually with some sugar sprinkled on top, making it somewhat similar to a danish. I was wondering how it would be with sour cream. I may also try a butterscotch filling in it, there's one in a Kringle recipe online that I've used in schnecken (Danish).