Melt chocolate in the microwave until smooth.
Pour into the molds and spread to coat. Do not fill entirely as you want them to be hollow.
Chill in fridge at least 10 mins or until they easily pop out.
On one half, sprinkle in the cocoa and load on some marshmallows.
Use some of the extra melted chocolate to brush on the edges and seal the two halves together.
Drizzle on some chocolate and add red/green sprinkles.
Let set.
Heat milk to just about boiling,
Place bomb in mug and pour on the milk until it cracks open!
Top with whipped cream, sprinkles, m & m's and sugar candies.
Stir and enjoy!