Step 1
In a heatproof bowl, combine the chopped chocolate, cocoa powder, heavy cream and corn syrup. Set the bowl over (not touching) simmering water in a saucepan and cook, stirring occasionally, until the chocolate has melted, about 10 minutes. Remove the bowl from the heat and stir in 1 1.2 cups (12 oz/ 375 g) of the yogurt. Let cool to room temperature.
Step 2
Meanwhile, in another bowl, stir together the remaining 1 1/2 cups yogurt, the sugar and vanilla.
Step 3
If using conventional ice pop molds, spoon 2 tbsp of the chocolate mixture into each mold. Top with 2 tbsp of the vanilla mixture. Add another 2 tbsp of the chocolate mixture and then another 2 tbsp of the vanilla mixture. Continue layering until the molds are full. Dip a paring knife into each mold and make a few figure-eight motions to swirl the flavors together. Cover and freeze until solid, at least 4 hours or up to 3 days. If using sticks, insert them into the molds when the pops are partially frozen, after about 1 hour, then continue to freeze until solid, at least 3 more hours.
Step 4
If using an instant ice pop maker, follow the manufacturer’s instructions to fill the molds, layering the mixtures as above, and freeze the pops.
Step 5
This popsicle recipe is reprinted with permission from <a href="http://www.weldonowen.com/food-drink/baking-desserts/ice-pops">Ice Pops: Recipes for Fresh and Flavorful Frozen Treats</a> by Shelly Kaldunski and published by Weldon Owen.
