Place the eggs in a mixing bowl or bowl of a stand mixer. Mix until the eggs are beaten together.

Add the cake mix, oil, and milk to the eggs. Beat on low speed for about 30 seconds until the dry ingredients are moistened. Then beat on medium high for 2 minutes.

Line a cupcake pan with paper cupcake liners and use a cookie scoop to add 3 tablespoons of batter to each cup.

Bake at 325 degrees for about 15 minutes until a toothpick inserted comes out clean. Remove from the oven and allow to cool.

Use a knife or a cupcake corer to remove the center of each cupcake.

Add the marshmallow cream to a piping bag or ziplock bag and use scissors to cut off the end. Pipe the marshmallow cream into the center of each cupcake.

Place the softened butter in the bowl of a stand mixer and beat until light and fluffy.

Add the hot cocoa mix and cocoa powder. Mix until combined.

Pour in the powdered sugar one cup at a time, mixing in between.

Add milk or heavy cream one tablespoon at a time until the frosting is the desired consistency.

Place the frosting in a piping bag with a large star tip. Swirl the hot chocolate frosting on top of each cupcake then top with a mini marshmallow, if desired.