Place the fresh raspberries in a fine mesh strainer. Press the raspberries with a spatula and continue to work it until all of the juice is in the bowl and only the seeds and some skin is left in the strainer. Discard seeds.
Add the granulated sugar into the raspberry puree. Stir to combine. Set aside.
In a mixing bowl, add in the yogurt, lemon juice, and lemon zest. Stir to incorporate.
Scoop the yogurt into four popsicle mold cavaties. Try to keep it even.
Put the raspberry puree into a cup with a spout or spoon it into the molds to the top. Using a knife or a skewer, poke the raspberry puree down into the yogurt mixture until it's mixed to your liking. Avoid stirring to get the swirled effect like mine.
Place the popsicle sticks or tops in. Freeze overnight until set.
Run hot water on the outside of the mold for about 30 seconds. Pull popsicles out and serve.
Notes
To store any leftover popsicles, place in the popsicle mold for up to 3 months!