Choose your chocolate wisely. For the easiest path, use compound chocolate or melting wafers—they don’t need tempering and still give a nice shine. If you prefer premium chocolate, plan to temper it for a snappy shell.

Melt the chocolate. Microwave in 15–20 second bursts, stirring often, until smooth. Keep the bowl dry and free of steam. Do not overheat; warm and fluid is enough.

(Optional) Quick temper for couverture chocolate. Melt two-thirds of the chocolate, then stir in the remaining one-third (finely chopped) until smooth and slightly thickened. Aim for about 88–90°F for dark and 86–88°F for milk chocolate.

Coat the molds. Spoon 1–2 tablespoons of melted chocolate into each cavity. Use the back of a spoon or brush to push the chocolate up the sides for an even coat. Chill for 5–10 minutes until set.

Add a second coat. Repeat with another thin layer, especially around the rim. This prevents cracking and leaks. Chill again until firm.

Release the shells. Gently peel the silicone back and pop out the half-spheres. Wear gloves to avoid fingerprints and melting.

Warm a plate. Heat a plate or pan until slightly warm (not hot). Press the rim of a half-sphere against it for 1–2 seconds to create a smooth, flat edge.

Fill the bottoms. In half of the shells, add 1–1.5 tablespoons of hot cocoa mix and a small handful of mini marshmallows. Add any flavor boosters now—crushed peppermint, a pinch of espresso powder, or cinnamon.

Seal the bombs. Warm the rim of an empty half-sphere on the plate, then place it over a filled half-sphere to seal. Lightly press together. If there are gaps, use a bit of melted chocolate as “glue.”

Decorate. Drizzle with melted white chocolate or leftover chocolate. Add sprinkles or crushed candy while the drizzle is wet. Chill a few minutes to set.

Serve the show. Place a bombshell in a large mug. Slowly pour 8–10 ounces of very hot milk over it. Stir as the shell opens and the cocoa and marshmallows bloom into a creamy drink.