Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a large bowl, combine the chocolate cake mix, eggs, chocolate milk, and vegetable oil. Mix for about 2 minutes until smooth.
Step 3: Line your cupcake pan with cupcake liners and fill each about two-thirds full with batter.
Step 4: Bake for 18-22 minutes until a toothpick comes out clean. Let cool for 5 minutes before transferring to a wire rack.
Step 5: Once cool, frost each cupcake with whipped white frosting using an offset spatula.
Step 6: Place halved marshmallows on top of each frosted cupcake, cut-side down.
Step 7: Add two brown Mini M&Ms on each marshmallow to create ghost eyes.
