Begin the ganache a day ahead to allow time for the fresh mint leaves to infuse their flavor into the cream. Need a shortcut? Skip the fresh mint infusion and make plain ganache frosting. Flavor it with a drop or two of mint oil or some peppermint extract, to taste.
Adapted from “Chewy Gooey Crispy Crunchy Melt-in-your-Mouth Cookies” by Alice Medrich.