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

Add 15-20 drops of green food coloring to the melted chocolate 5-6 drops at a time and stir to incorporate the dye.

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

Spoon 1 tablespoon of melted chocolate into each well of the mold. Using the back of a spoon, spread the chocolate up the sides of each well, 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 the chocolate filled mold in the fridge and let it sit for 10 minutes, until chocolate has hardened.

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.

Take one half of the chocolate bomb and position it on a cookie sheet. Fill this half with 2 tablespoons of hot cocoa powder and 6-8 mini marshmallows.

Warm a small plate in the microwave, then place the bomb mold halves, edge side down, on the hot plate. 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.

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.

For decoration, drizzle any leftover green melted chocolate over the top of the hot cocoa bomb and apply the red heart offset from the top center.