Ingredients:

Chocolate (milk, dark, white, etc.)

Hot chocolate mix

Optional add-ins (marshmallows, sprinkles, ect.)

Silicone sphere mold

Steps:

1. Melt your chocolate by microwaving it in a bowl for 30 seconds, stirring, then continuing to heat at 15-second intervals, and stir until the chocolate is all melted.
2. Use a spoon to dollop the melted chocolate into your molds, smoothing it around the edges until everything is covered. Set in the refrigerator for about 30 minutes, or until the chocolate is firm.
3. Fill half of your molds three-fourths full with your hot cocoa mix and optional add-ins. The other halves will be used to close the bombs.
4. Use a low heat to warm the pan on the stove. Once the pan is warm take an empty half and place it on the pan to melt down the edges but only a little.
5. After the edges are melted stick it to the full half and let it cool.
6. Once cooled your bomb is ready to use!
7. Heat milk and place the bomb in the milk. Watch the hot chocolate bomb explode open to create delicious hot chocolate!

Sources: 

https://www.allrecipes.com/article/hot-chocolate-bomb-molds/