I’m glad you asked, reader Katie, because I forgot to make a note about it. Fiori di Sicilia is an extract that combines vanilla, citrus and flower essences. “Flowers of Sicily” is what it literally means. I’ve looked around and can’t determine for certain if Italians use this exact product in their panettone baking, however it seems clear that extracts containing flower essences are fairly common there. The dominant flavors in Fiori di Sicilia are vanilla and orange, so a combination of those two make a fine substitute. Also a little rose flower water, if you can find some of that, will make up for some of the floral aromas. But don’t be afraid to omit it entirely, because to be honest it can be just too darn strong for some people. It nearly is for me!