01 - Place semi-sweet or dark chocolate in a heatproof bowl over simmering water. Stir continuously until smooth and fully melted.
02 - Spoon about 1 tablespoon of melted chocolate into each sphere mold cavity (2.5–2.75 inches diameter). Use a brush or spoon back to evenly coat sides. Refrigerate for 10 minutes to set.
03 - Apply a second layer of melted chocolate in molds to strengthen shells. Chill again in refrigerator for 10 minutes until fully set.
04 - Carefully remove chocolate shells from mold, handling gently to avoid cracks.
05 - Add 1 tablespoon hot cocoa mix, mini marshmallows, and crushed peppermint into half of the shells (6 total).
06 - Warm a plate slightly. Press edges of empty shells onto the warm plate briefly to soften, then fit over filled shells and press gently to seal completely. Repeat for all bombs.
07 - Drizzle melted white chocolate over sealed bombs and sprinkle with extra crushed peppermint candies. Allow to set before serving.
08 - Place one cocoa bomb into a mug, pour 1 cup (250 ml) hot milk over it, stir well to dissolve, and enjoy.