In a microwave-safe bowl, melt half of the milk chocolate chips in 30-second intervals, stirring in between until smooth.
Using a spoon, coat the inside of the silicone mold with the melted chocolate. Make sure to cover the entire surface, then place the mold in the fridge for about 10 minutes to set. Repeat this process to ensure the shells are thick enough.
In a separate bowl, mix cocoa powder and optional sugar. Add a tablespoon of the mixture into each chocolate shell. Top with mini marshmallows and a sprinkling of crushed peppermint candy canes if using.
Melt the remaining milk chocolate chips and use it to 'glue' the two halves of the chocolate shell together. Seal well and smooth any excess chocolate around the seam.
Place the filled molds back in the fridge for an additional 10 minutes to allow the bombs to set completely.
Carefully remove the cocoa bombs from the silicone mold. Make sure to handle them gently to avoid cracking.
To enjoy, place a cocoa bomb in a mug and pour over hot milk, watching it melt and release the marshmallows and cocoa powder!
Notes
Package the cocoa bombs in a clear bag and tie with a festive ribbon for a delightful gift.
Keyword chocolate, dessert, holiday treat, hot cocoa