Melt chocolate candy discs. You can use chocolate chips for this. However, you may need to add a teaspoon of coconut oil or shortening to the chocolate to get it to spread smoothly. Chocolate candy discs that have already been tempered are the best choice.
Completely fill all 6 cavities of your silicone mold. Set aside for 5 minutes.
Spill the excess chocolate from the silicone mold. The shell should be thick enough not to need a second chocolate coat.
Turn mold over and let chill upside down for 5-10 minutes in the refrigerator.
Unmold chocolate shells and add powder and marshmallows to one half of each shell.
Using a griddle on low heat or a warm plate, heat the rim of the second half of the chocolate mold and place it on top of the first to make a full sphere. Depending on the size and coats of chocolate, you should end up with 3-4 hot chocolate bombs.