In a large microwave-safe bowl, warm the milk chocolate as instructed on the package until it melts. Stir until smooth.

Place the silicone mold on a baking sheet or cutting board.

Spoon 1 tablespoon of melted milk chocolate into each well of the mold. Using the back of a spoon, spread the chocolate up the sides of the mold, creating a complete layer that covers the entire mold. As the edge starts to harden, spread some more chocolate to thicken the edge. Pour out any excess chocolate that pools on the bottom of the mold.

Place chocolate mold in the fridge and let it sit for 10 minutes, or until chocolate has firmed up.

Remove the mold from the fridge and carefully flip it over so that the rounded side is facing up.

Gently press the center of each well and peel the silicone mold away from the hardened chocolate shell. Be cautious not to apply too much pressure to avoid cracking the shell.

Warm a plate in the microwave then place one half of the chocolate shell, edge side down, on the heated surface. Allow the edge of the shell to melt slightly until it creates a smooth and even edge that can be used to seal the bomb.

Take one half of the chocolate bomb and position it on a cookie sheet. Fill this half with 1 tablespoon of hot chocolate mix and 6-8 mini marshmallows.

Place the other half of the chocolate bomb on the heated plate. Carefully position it on top of the filled shell. The melted edges of the chocolate will meet and serve as a "glue" to secure the two halves together.

In a microwave-safe container, warm the white chocolate candy melts as instructed on the package until it melted. Stir until smooth.

Place melted white chocolate in a piping bag and drizzle over the top of the bombs. Add Christmas sprinkles to the hot cocoa bomb while the drizzle is still wet.

Allow drizzle to harden and store hot cocoa bombs in an air tight container.