Weird Buffy reference in The Dresden Files

I’m listening to the audiobook for Peace Talks, the 16th book of the Dresden Files series, and Harry Dresden quotes, of all things and apropos of nothing “that’ll put marzipan in your pie plate, bingo.” I know Jim Butcher is a Buffy fan, it’s been referenced before, and there’s more-than-a-little of Buffy in The Dresden Files’s DNA, but still, what a strange line to reference. lol Made even better for the fact that James Marsters narrates all the Dresden Files audiobooks