"Blunt Instruments," by James Powell, in Ellery Queen's Mystery Magazine, January 2014.
I say this with great fondness and admiration: Jim Powell is a nut. Exhibit A is the latest of a long line of stories he has written in honor of Christmas, one more fantastical than the next. Plots against Santa Claus, plots by Santa Claus...
This story involves two professors at the University of Toronto and a theory for the origin of that most inexplicable piece of the holiday experience: the fruitcake. I won't go further except to say that the origin is Not Of This World.
The story barely qualifies as a mystery - or putting it another way, Powell tucks in a crime to make it fit into EQMM when it might otherwise have been happier in a fantasy magazine. But I am not complaining, because if it had shown up there I might not have had the chance to read it, or report it here, and that would have been a shame.