6 ounces milk chocolate melts, chocolate chips, or chopped bar chocolate
1/3 cup hot cocoa mix
2 ounces dark chocolate melts or dark chocolate chips, melted, for drizzling
Additional fillings and toppings, as desired
Microwave the chocolate in a microwave-safe bowl for 30 seconds. Stir and microwave again, i 15 second intervals, sitrring inbetween, until the chocolate is melted. Alternatively, melt using a double boiler on the stovetop.
Using the back of a spoon or a pastry brush, fully coat the inside of a half-sphere mold with chocolate. Transfer to the freezer to harden for 5 minutes and then paint with a second layer of melted chocolate, concentrating especially around the edges and sides to thicken the shell. Place in the freezer once more until firm, about 5 more minutes. Repeat as needed if there are any thin spots or holes.
Gently remove the chocolate half-spheres from the molds. Place half of the half-spheres in cupcake cups to hold steady and fill with 1 tablespoon of hot cocoa mix and marshmallows, as well as any additional fillings you’d like to include.
Microwave a microwave-safe plate for 90 seconds. One at a time, take one of the remaining unfilled half-spheres and gently press and twist on the hot plate to melt and smooth the edges. Place on top of a filled half-sphere to create a whole sphere.
If any gaps remain, use a butter knife to gently fill cracks and creases with melted chocolate from the hot plate.
Drizzle with melted dark chocolate and top with additional mini marshmallows, or decorate as desired.
To serve, place a hot cocoa bomb in a mug and pour over very hot milk or hot water to melt the bomb. Stir to combine and enjoy!