I recently spent a few days in Stockholm. I've spent a fair bit of time there, and I can work my way round a cake menu with a reasonably adept eye. I'd never been there at this time of year before, so I was delighted to make the acquaintance of a cake new to me, the semla (plur: semlor).
The semla is a hollowed-out bun, filled with a mix of milk, almond paste and breadcrumbs. This is covered with whipped cream, then the top of the bun is replaced, dusted with powdered sugar. The semla is traditionally served in warm milk. Although I didn't try them with warm milk I ate several during my stay, and I can confirm that they are as fantastic as they sound.
But this isn't (just) about my taste in cakes. Semlor are traditionally a cake for Shrovetide, before the Lent fast. ('Semla' comes from the German 'semmel', and is etymologically cognate with the Shrovetide Simnel cake here in Britain). After the Reformation in Sweden semlor became more generally cakes eaten between Shrovetide and Easter.
On returning to London we checked out the availability of semlor in a Scandinavian café here. They had been available, but only until Shrove Tuesday itself. None of this available till Easter stuff here.
This is consistent with the invention and adaptation of traditions to express a national identity away from home. Rather than the constant development of a tradition we begin to see a more rigid codification of one. (In a rather different sphere, one could point too to the strict exclusion of LBGT banners from American St Patrick's Day parades organised by the Ancient Order of Hibernians: such an exclusion took place even as these banners became a more familiar sight in Ireland itself).
This is interesting from a folkloric perspective. Sadly, it's not getting me another semla this year.