Melt the caramel candy melts in a double boiler or in a microwave safe bowl in the microwave. Stir until smooth.
Spoon the melted caramel candy into the inside of 12 (2-inch diameter) silicone sphere molds. Refrigerate for 5 minutes until the candy is set, and then repeat this process to thicken the candy spheres. Refrigerate for 5 minutes, and then gently remove the candy from the molds.
To each of 6 candy half spheres, add the following: 1 tablespoon hot cocoa, 4 mini marshmallows, and 2 caramel quarters.
Heat a pan until warm and then remove it from the heat. To seal the hot cocoa bombs, place a half sphere on the hot pan so it melts slightly on the edge. Carefully pick up the half sphere with the slightly melted edge and place it on top of a sphere filled with hot cocoa, marshmallows, and caramel. Run your finger along the outside to smooth it out. Repeat this process until you have 6 hot cocoa bombs.
To decorate the hot cocoa bombs, place them on a tray or piece of wax paper.
Melt the white candy melts in a double boiler or in a microwave safe bowl in the microwave. Stir until smooth. Pour the melted white candy into a small zip-top plastic bag and cut off one tiny corner. Gently squeeze the melted white candy onto the tops of the hot cocoa bombs in a decorative drizzle. If desired, top with sprinkles before the melted white candy sets.
To serve, add a hot cocoa bomb to a mug. Pour in 8 to 10 ounces of hot milk, stir, and serve.
Notes
As with any candy or chocolate, it's best to keep these in a cool, dark place, away from heat and direct sunlight. You can store them in the refrigerator if you will have them for longer than a few days.