In a small bowl or measuring glass, stir together the hot coffee and cocoa powder until a smooth chocolate syrup forms.
Add the Greek yogurt, chocolate syrup, maple syrup, vanilla, and salt to a blender, then pour in the chocolate mixture.
Blend until completely smooth and creamy.
Pour the mixture into popsicle molds, leaving a little space at the top for expansion as they freeze. Gently tap the molds on the counter to remove any air bubbles.
Add the lid and sticks if your molds have them. If not, cover the molds with foil or plastic wrap and insert the sticks through the top so they stay upright.
Freeze for at least 6 hours, or until fully solid.
To remove the popsicles, gently press from the base of the mold while pulling on the stick. If needed, run the outside of the molds under warm water for a few seconds to help loosen them.
Store frozen for up to 1 month.