Combine the sugar, salt, and ½ cup water in a 2-quart saucepan over medium heat. Bring to a boil and make sure the sugar has dissolved. Remove from the heat and let the syrup cool completely. Transfer the syrup to a 1-quart liquid measuring cup.

Puree the strawberries in batches in a blender. Measure out 1 cup of puree (save any extra for another use) and combine it with the syrup. Stir in the yogurt until well-combined.

Distribute the pineapple  among ten ⅓-cup pop molds. Add the fruit mixture to each mold, leaving about ¼ inch at the top to allow for expansion. Stir gently with a Popsicle stick to distribute the pineapple. Freeze until partially frozen, about 1 hour. Insert sticks and freeze again until the pops are fully set, 4 to 6 hours more. (I did mine all in one step).

To unmold, dip the mold in a deep pan of hot water until the pops pull out easily, 30 to 40 seconds, or let sit at room temperature for 5 to 10 minutes.