Adapted, just a bit, from On A Stick!
Makes 4 standard-sized popsicles (3 ounces each) or 6 in my tiny* popsicle molds (which were 2 ounces each)
2 tablespoons (21 grams or 3/4 ounce) semisweet chocolate chips or chopped semisweet chocolate
1/3 cup (67 grams or 2 1/3 ounce) sugar
1 tablespoon (7 grams or 1/4 ounce) cornstarch
1 1/2 tablespoons (8 grams or 1/4 ounce) unsweetened cocoa powder
1 1/4 cups (300 ml) whole milk
Pinch of salt
1/2 teaspoon (3 ml) vanilla extract
1/2 tablespoon (7 grams or 1/4 ounce) unsalted butter
In the bottom of a medium saucepan over very low heat, gently melt the chocolate chips, stirring constantly until smooth. Stir in sugar, cornstarch, cocoa powder, milk and salt and raise heat to medium. Cook mixture, stirring frequently until it thickens, anywhere between 5 minutes (for me) and 10 (suggested in the book). Remove from heat, add vanilla and butter and stir until combined.
Set aside to cool slightly then pour into popsicle molds. Freeze 30 minutes, then insert popsicle sticks. Freeze the rest of the way before serving.