Add 10 oz chopped chocolate to a medium microwave safe bowl and microwave for 30 seconds. Remove from the microwave, and stir as much as you can. **
Continue to microwave in 15 second intervals, stirring fully and scraping the sides of the bowl with a rubber spatula between each time, until the chocolate is almost completely melted. Then continue to stir the chocolate so that it's continues to melt from it's own heat until it is fully melted, without over heating it.
Once the chocolate is smooth, check the temperature with an instant read thermometer to make sure that the melted chocolate reads between 88 and 90 degrees Fahrenheit (for semi sweet or dark chocolate) If the temperature goes over 90 degrees, stir in an additional ounce or two of chopped chocolate, without reheating to lower the temperature. (If you're using milk chocolate you want it melted between 86 and 88 F)
Spoon about 1 Tablespoon of melted chocolate into each of the hot chocolate molds.Use the back of a small spoon to spread it around. Make sure to get the chocolate all the way to the top of the rim, and to cover any exposed areas.
Place the molds on a small baking sheet and refrigerate for 5 minutes.
Remove the molds from the fridge and spoon another heaping spoonful of melted chocolate into each half dome. Use the back of the spoon to work the second layer of chocolate around, really building up the edges to make them thicker, to help them not to crack. Repeat with additional half domes.
Place the molds into the freezer to chill for 10 minutes.
Remove the molds from the freezer and put on food safe gloves to carefully remove the shells from the mold. (The gloves keep the chocolate shells from getting any finger prints on them)
Once all 12 shells are made, microwave a flat microwave safe plate for 2 minutes.
Place 6 of the shells on the plate, one at a time, and use your gloved hand to gently spin them on the plate, to smooth the edges.
Place the round side down in a regular cupcake liner to hold the hot cocoa bombs.
Wipe the plate clean.
Fill the shells in the cupcake liners with about 1.25oz, or 3 TBS of the caramel hot chocolate mix, and as many marshmallows as you want/can add.
Reheat the plate for another 2 minutes in the microwave.
Then repeat the process with the remaining 6 shells, and place them on top of the filled halves. Gently press them down to seal them together.
Let the hot chocolate bombs set for a few minutes.
Add caramel candy melts to a small microwave safe bowl, and melt them in 30 second increments.
Add caramel candy melts to a ziptop bag and snip the corner off. Drizzle it over the top of the hot chocolate bombs.
Top with sprinkles and sea salt, if desired.