Place the candy canes in a zip lock bag and crush them with a rolling pin until they are just small crumbs. Alternatively, you can place them in a blender or food processor and pulse a few times.
Melt the white chocolate using one of the methods below.
Place the silicone moulds on a baking sheet and add working one at a time, add approximately 1 tablespoon of melted chocolate to each cavity and use a small pastry brush to coat the inside of the mould making sure it is fully coated.
When all cavities have been coated place the pan in the freezer for about 5 minutes or until the chocolate is firm.
Remove the pan from the freezer and repeat the process of brushing chocolate in the cavities, this time using 1-2 teaspoons of chocolate per cavity paying special attention to make sure it reached the edge of the moulds. Be sure to reserve a bit of chocolate for decorating the chocolate bombs.
Place the pan back in the freezer for 5 -10 minutes until fully set.
Fill a mug with boiling water and place a small clean plate on top.
Carefully stretch the silicone moulds to loosen the chocolate from the cavities, but do not remove them.
Scoop approximately 1 tablespoon of hot chocolate mix into 6 chocolate moulds, then add 1/2 - 1 teaspoon of crushed peppermint candy and a few marshmallows.
Working one at a time remove an empty shell from the mould and place it face down on the warm plate. When you see melted chocolate form on the edge, remove it from the plate and immediately place it over a filled mould. Press gently to fuse the edges together. Repeat with remaining shells.
When all the chocolate bombs are sealed place the pan back in the freezer for a few minutes to allow the halves to set. Then remove the tray from the freezer and pop the cocoa bombs out.
Drizzle with remaining melted chocolate and decorate as desired.