Prepare and bake the cupcakes according to package instructions, or using your favorite homemade chocolate cupcake recipe. Cool completely.
In the bowl of a stand mixer, cream together the butter, vanilla extract, and peppermint extract until smooth, about 1 minute. Gradually add in the confectioners' sugar, one cup at a time, alternating with the heavy whipping cream until frosting is light and fluffy. Add in a drop or two of liquid green food coloring, tinting it to your desired shade.
Pipe or spread the frosting onto the cooled cupcakes. Note that if you pipe the frosting as high on the cupcakes as I did, you may want to double the frosting recipe.
For the ganache: add the chocolate chips to a small bowl. Microwave the heavy cream for about 30-45 seconds or until hot. Pour the heavy cream over the chocolate chips and let stand for about 5 minutes. Stir until combined, glossy and thick. Spoon a little bit over each cupcake and allow it to drip down the sides. Top with an Andes mint.