Rum, lime zest, and fresh mint infuse this cupcake frosting recipe will all the flavors of a mojito cocktail. Try it on top of homemade chocolate cupcakes for an adults-only dessert.
Allow butter and eggs to stand at room temperature for 30 minutes. Meanwhile, in a small saucepan combine milk and chocolate. Cook and stir over medium-low heat until chocolate is melted; cool.
Grease and flour twenty-eight 2-1/2-inch muffin cups (or line with paper bake cups). In a medium bowl stir together flour, baking soda, baking powder, and salt. Set aside.
Preheat oven to 350 degrees F. In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Gradually add sugar, about 1/4 cup at a time, beating on medium speed until combined. Scrape sides of bowl; beat for 2 minutes more or until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in creme de menthe and vanilla. Alternately add flour mixture and chocolate mixture, beating on low speed after each addition just until combined. Beat on medium to high speed for 20 seconds more.
Spoon batter into prepared muffin cups, filling each about three-fourths full. Use the back of a spoon to smooth out batter in cups.
Bake about 20 minutes or until tops spring back when lightly touched. Cool cupcakes in muffin cups on wire racks for 5 minutes. Remove cupcakes from muffin cups. Cool completely on wire racks.
To make the frosting, sprinkle the rum over the powdered gelatin in a 1-cup glass measuring cup. When the gelatin has set, heat it in the microwave for 10 seconds (or until liquid) and then combine with the whipping cream, sugar, lime zest, and crème de menthe in a large mixing bowl, beating constantly with an electric mixer on medium speed. Continue beating on medium to high speed until stiff peaks form (tips stand straight). Pipe on cupcakes and garnish with mint leaves and more lime zest. Makes 28 (2-1/2 inch) cupcakes.
If using white creme de menthe, add 1 or 2 drops green food coloring.