In a medium bowl, whisk together cocoa powder, sugar, cornstarch, and salt until well blended.

Gradually pour in half of your milk while whisking continuously to form a smooth mixture. Once combined, add the remaining milk and mix thoroughly.

Transfer the mixture to a saucepan and heat over medium heat, stirring constantly for about 5-7 minutes until it thickens.

Remove from heat and stir in vanilla extract. Allow to cool for 5-7 minutes.

Carefully pour the chocolate mixture into popsicle molds, filling them to about 3/4 full.

Insert popsicle sticks into the center of each mold and freeze for at least 8 hours.

Once frozen, remove pops from molds by running warm water over the outside.