- 1/2 cup unsweetened cocoa powder (natural or Dutch-processed)
- 1/2 cup granulated sugar
- 1 tablespoon cornstarch
- 1/4 teaspoon kosher salt
- 2 cups dairy or non-dairy milk
- 1/2 teaspoon vanilla extract
Combine the dry ingredients. Place 1/2 cup cocoa powder, 1/2 cup granulated sugar, 1 tablespoon cornstarch, and 1/4 teaspoon kosher salt in a medium saucepan and whisk to combine, breaking up any clumps.
Whisk in the milk. Slowly whisk in 1/2 cup of the milk or non-dairy milk and whisk until smooth. Whisk in the remaining 1 1/2 cups milk until smooth.
Simmer the mixture until thickened. Bring the mixture to a simmer over medium heat, stirring constantly with a rubber spatula to prevent the milk from burning. Simmer until the mixture thickens and coats the back of the spatula (it should be the consistency of chocolate sauce), about 1 minute. Remove from the heat and stir in 1/2 teaspoon vanilla extract. Let cool, stirring occasionally, for 5 minutes. The mixture will continue to thicken as it cools to become the consistency of warm pudding.
Divide between popsicle molds and freeze. Divide the mixture between 8 (2 to 2.25-ounce) Popsicle molds. Insert a Popsicle stick in each mold and freeze until completely solid, at least 6 hours.
Unmold and serve. Run cool water over the molds to unmold and serve.