Melt the chocolate, then place about 2 tablespoons into each mold. Using a spoon or pastry brush, distribute the chocolate so it coats the inside of each mold evenly.
Place in the freezer for 5 minutes, and then add a second coat of chocolate to each mold. Place back into the freezer for another 5 minutes.
Carefully remove the chocolate from the molds.
Then, using a warm pan, place 4 of the halves one by one onto the pan to even out the edges.
Fill each of these half circles with 2-3 tablespoons of hot chocolate mix. Add in a pinch of peppermint candies and a small handful of marshmallows.
Take an empty half circle and even out the edges on the warm pan. Immediately place that half on top of one of the filled halves. Hold and press for 10 seconds to help the chocolate stick. Repeat this profess with the remaining three.
Decorate your formed bombs with drizzled melted white chocolate, sprinkles, and crushed candy as desired.
When you are ready to use your hot chocolate bomb, place it in a mug and pour one cup of warm milk on top.