01 - Melt the chocolate in a microwave-safe bowl in 30-second intervals, stirring between each, until smooth. Alternatively, melt over simmering water using a double boiler.
02 - Using a pastry brush or spoon back, coat the inside of twelve 2-inch diameter silicone half-sphere molds generously with melted chocolate.
03 - Refrigerate molds for 10 minutes to set. Apply a second chocolate layer to strengthen shells, then chill again until fully firm, approximately 10–15 minutes.
04 - Carefully remove the chocolate half-spheres from the molds.
05 - Fill six half-spheres with one tablespoon of hot cocoa mix and approximately ten mini marshmallows each.
06 - Warm a plate briefly in the microwave. Press the edge of an empty half-sphere against the warm plate to slightly melt the rim, then immediately seal onto a filled half-sphere to form a complete bomb. Repeat for all molds.
07 - Drizzle with extra melted chocolate or sprinkle with festive toppings. Allow to set.
08 - Place a cocoa bomb in a mug and pour 1 cup (250 ml) of hot milk over it. Stir until fully dissolved and enjoy.