I'm wrong -- it's a Cosmo-flavored cupcake. It's filled with strawberry buttercream and has lime creamcheese icing.

Crumbs' best cupcakes are the apple & honey ones they sell during the high holidays every year, though. They're not listed on the website because they only have them for about a week each year, but they're amazing. Like, sold-out-after-the-first-day amazing.