Preheat the oven to 350 degrees Fahrenheit and line two cupcake tins with black cupcake liners.
Mix together the cake mix, eggs, chocolate milk and vegetable oil in a large mixing bowl until completely combined, about 2 minutes.
Scrape the sides and bottom of the bowl occasionally with a spatula.
Scoop the cupcake batter into the prepared cupcake tins, filling each liner about ⅔ full with batter. Do not overfill.
Bake for 18-25 minutes or until a toothpick inserted in a cupcake comes out clean.
Allow the cupcakes to cool completely before decorating.
To decorate the cupcakes, place one half of a marshmallow on the middle of the top of each cupcake.
Scoop the frosting into a piping bag prepared with a 2A Wilton tip.
Pipe the frosting around the bottom of the marshmallow and then gradually move inward creating an ice cream type spiral of frosting on the cupcake.
Place two brown mini M&Ms on the front of the spiral as eyes.
Repeat with each cupcake until they are all decorated.