Melt the white chocolate melting chips and spoon a small amount into the molds.
Using a paintbrush, spread the chocolate evenly around the mold, making sure to get all the way up to the edges.
Allow the chocolate to harden, then repeat this step until you have done about 3-4 layers in each mold.
Allow the chocolate to harden completely, about 5 minutes, then gently remove them from the molds.
Fill one side of the shell with 2 teaspoons of hot chocolate mix and mini marshmallows.
Heat a microwave-safe plate in the microwave, then place the second half of the chocolate shell open-side down onto the plate to slightly melt the rim.
Quickly place the two open ends together and smooth out any extra chocolate around the seam. Allow it to cool.
While the cocoa bombs cool, melt the chocolate chips, and orange melting candy, then use them to decorate each snowman hot cocoa bomb with eyes, a nose, and a smile.
You can also melt the blue melting candy and place it in a small Ziploc bag with a tiny whole cut in the corner to drizzle it over the bombs.
To serve, place a hot cocoa bomb in the bottom of a mug. Pour warm milk over the top to melt the chocolate and reveal the hot chocolate within.