If you want, you can use the lime peel to make candied lime peel for the top of the cupcakes. Mix 1/2 cup sugar with 1/2 cup water and boil until it starts to thicken. Add thinly sliced strips of lime peel and cook until the mixture is very thick. Allow zest to stay in the syrup for 10 minutes, then carefully remove and place on wax paper. After applying frosting, decorate with the lime peel.
Adapted from Adapted from David Lebovitz’ Ready for Dessert