Melt the chocolate and spoon a small amount into the mold

Using the paintbrush, spread the chocolate evenly around the mold, making sure to get all the way up to the edges

Allow chocolate to harden and repeat layering on more chocolate until you have done about 3-4 layers

Allow chocolate to be completely hard, 5 minutes, then gently remove it from the mold

Fill one side of the shell with 2 teaspoons of hot chocolate mix and mini marshmallows

Heat a microwave-safe plate and place the second half of the chocolate shell open-side down onto the plate to melt the rim

Quickly place the two open ends together and smooth out any extra chocolate around the seam

Place in a mug and pour warm milk over the top to melt and reveal the hot chocolate within