Step 1

Put the chocolate chips into a medium glass mixing bowl. Set aside.

Step 2

Combine the milk, cocoa powder, sugar, vanilla and 1/4 teaspoon salt in a medium saucepan over medium heat. Whisk constantly until the cocoa is dissolved and the mixture comes to a simmer, 5 to 7 minutes. Remove from the heat and pour the milk mixture over the chocolate. Let stand for 5 minutes, then whisk gently until all the chocolate is melted. Whisk in the yogurt until smooth and blended, then cool completely.

Step 3

Divide the mixture evenly among eight popsicle molds (about 1/3 cup per pop) and freeze until solid, at least 5 hours. (They'll keep up to a month.) Just before serving, briefly run the molds under hot water to release the pops.