In a glass bowl, melt the chocolate in the microwave for 15 second bursts, stirring after each burst, until melted and smooth.
Use a pastry brush to brush 12 semi-spheres with a thick layer of the melted chocolate. Place the molds in the freezer for 5 to 10 minutes to allow the chocolate to set. I recommend brushing a double layer in order to create thick shells.
Once cold and solid, remove 6 of the semi-spheres from the mold and transfer them to a rimmed baking sheet that has been lined with wax paper. Fill each with a couple of spoonfuls of the hot cocoa powder, a few mini marshmallows and a few mini Peppermint Patties.
Run a plate under hot water until it’s warm to the touch. Take out the other 6 semi-spheres from the freezer, and gently place an open edge on the plate until it begins to melt slightly. Cover a chocolate-filled half with the empty, melted edge half to seal the chocolate bomb. Rub the chocolate with your fingers to seal (grab some melted chocolate from the plate if you need to). Repeat with the remaining ingredients. Let the bombs sit until the chocolate is set (or place into the freezer to set more quickly).
Place the leftover melted chocolate in a pastry bag. Pipe the milk chocolate over the Cocoa Bombs and sprinkle with chopped mints.
USE THE BOMBS FOR HOT CHOCOLATE:
Heat 1 cup of milk, and pour into a mug (use microwave or on stovetop). Place one Hot Chocolate Bomb in the bottom of the mug, and pour the heated milk over the top. The Hot Chocolate Bomb will melt and bubble, and marshmallows will float to the top. Stir the powdered cocoa and mints into the milk, top with whipped cream and a few more marshmallows, if desired. Enjoy!