01 - Place the semi-sweet or dark chocolate in a heatproof bowl over simmering water. Stir continuously until fully melted and smooth.
02 - Spoon approximately 1 tablespoon of melted chocolate into each cavity of a silicone sphere mold (2.5–2.75 inches diameter). Use a brush or the back of a spoon to coat the sides evenly. Refrigerate for 10 minutes.
03 - Repeat the coating process to reinforce the shells. Chill again for 10 minutes until completely set.
04 - Carefully unmold the chocolate shells to prevent cracking.
05 - Place 1 tablespoon of hot cocoa mix, a handful of mini marshmallows, and a sprinkle of crushed peppermint candies into 6 shells.
06 - Warm a plate slightly and press the edge of an empty shell onto it for a few seconds to soften. Immediately place it over a filled shell and press gently to seal. Repeat for all shells.
07 - Drizzle melted white chocolate on top and sprinkle with extra crushed peppermint candies if desired. Allow decoration to set.
08 - Place a cocoa bomb in a mug, pour 1 cup (250 ml) of hot milk over it, stir well, and enjoy.