Pour candy melts in a microwave safe bowl and heat for 30 seconds or until melts have fully melted.
Spread the candy melts up the sides of the mold until every bit of the mold is covered.
Let the molds sit about 5 minutes & re-spread any of the candy melts that sank to the bottom of the molds.
Place the molds in the refrigerator for about 30-45 minutes.
Once set, carefully remove the candy melt spheres from the mold.
Fill half of the spheres with the hot cocoa powder & marshmallows.
Place a glass plate in the microwave for one minute.
Remove the plate and immediately place each empty sphere on the hot place to heat the chocolate edges.
Place each heated sphere on each filled sphere. You can use the tip of your finger to smooth the melted candy around the seam.
While your cocoa bombs set, re-heat the left over candy melts.
While the Candy is still hot, place conversation hearts on the bomb. The candy melts will act as a glue.