In a medium heavy pot, combine chocolate, sugar, butter, and a pinch of salt over low heat. Stir until melted together. Don’t let the mixture boil.
In a separate bowl, sprinkle gelatin over half and half and let sit for 5 minutes, then stir together to combine.
When gelatin is combined, slowly whisk into the chocolate mixture. Return to low heat and whisk slowly until mixture is combined. Don’t overheat the mixture. It shouldn’t go above 170 degrees F.
Transfer pudding mixture to blender and pulse a few times to combine well.
Slice cantaloupe with a very sharp knife. Try to get the slices thin enough that you can see light through them. Press slices into the popsicle molds, trying to keep the cantaloupe to the outer edges of the mold.
Pour pudding mixture into molds. Use a stick to make sure no air bubbles form in the mold. Insert popsicle tops or sticks and freeze solid.
Run pudding pops under warm water for a few seconds to loosen the pops when ready to eat!