Place white chocolate candy melts in a microwave safe bowl and melt in the microwave per the directions on the package.
While the chocolate is melting, sprinkle a generous amount of the white edible glitter in each of the mold cavities, shifting it around to coat the entire mold.
Place 1 tablespoon melted candy melt into one half of a bomb mold and, using the bottom of your tablespoon measuring spoon, press the chocolate up the sides of the mold, keeping it thick but even. Repeat with 12 bomb mold halves. Reserve the remaining melted chocolate.
Place the chocolate filled bomb molds into the freezer for 5 minutes.
Remove molds from the freezer and gently peel the silicone away from the chocolate cups.
If the edges of the chocolate cups are not even, heat a plate or a flat-bottom bowl in the microwave until the surface of the plate is warm to the touch. Press one of the empty chocolate bomb halves open-side-down onto the flat portion of the warm plate for about 10 seconds. This will gently melt the rim of the chocolate cup and even it out. Repeat with all of the chocolate cups, as necessary.
Fill 6 of the molds with 1 tbsp white hot cocoa mix and 5-10 mini marshmallows.
Heat a plate or a flat-bottom bowl in the microwave until the surface of the plate is warm to the touch. Press one of the empty chocolate bomb halves open-side-down onto the flat portion of the warm plate for about 10 seconds. This will gently melt the rim of the chocolate cup.
Immediately press this warmed edge chocolate cup to the top of one of the filled cups. This will join the two halves of the hot cocoa bomb.
With the reserved chocolate, pipe a little bit of the melted chocolate on top of each hot cocoa bomb and immediately sprinkle additional edible glitter on top of the melted chocolate.
Place the hot cocoa bombs into the freezer for 5 minutes to get them to set, then remove and store in an airtight container until you’re ready to use.