In a blender, combine the cashews and boiling water. Blend on high until smooth and creamy. Add in orange slices, vanilla, agave or maple syrup, and sea salt. Blend again on high until completely smooth. This makes 3 cups.
Pour 1½ cups (half) of the mixture into the bottom of a popsicle mould, dividing evenly between 8 moulds. With the remaining 1½ cups left in the blender, add in the cocoa powder, blend again for a few moments until combined. Pour this mixture over the orange mixture, dividing evenly. Stick in your popsicle sticks and freeze for at least 4 hours.
Release the popsicles out by running hot water around the mould, being sure not to get the popsicles wet! Store in a parchment-lined container in the freezer or enjoy immediately.