Preheat the oven to 350 degrees F. Insert liners into a medium cupcake pan.

In a large bowl cream together the butter and sugar with an electric mixer on medium speed until light and fluffy, 3-5 minutes. Beat the melted chocolate into the butter mixture. Add the eggs, perppermint extract, and chocolate milk. Beat until creamy.

In a separate medium-sized bowl combine the flour and baking soda.

Add the dry ingredients to the chocolate mixture and beat until well blended. With a rubber spatula, stir in the chocoalte chips.

Fill the cupcake liners 3/4 full. Bake for 15-20 minutes or until a toothpick inserted in the center of cupcakes comes out clean. Cool cupcakes in the pan.