Macerate the fruit. In a large mixing bowl, stir together strawberries, raspberries and sugar. Let sit at room temperature for 15 minutes. Mash gently with a potato masher, but do not over-mash to the point of a puree. The resulting mixture will be juicy with large chunks remaining.
Prepare yogurt mixture. In another bowl, stir together Greek yogurt and milk to thin the yogurt and help it freeze. Stir in agave or honey until combined.
Prepare granola mixture. Add granola to another bowl, and stir in 1/4 cup of the yogurt mixture.
Make the layers and freeze. Spoon in the mixtures in six layers into clean and dry popsicle molds. Start with the yogurt mixture, then the granola mixture, then the fruit mixture — filling the molds halfway. Place on a level shelf in the freezer. Allow to set up, about 15-30 minutes. Remove from freezer and insert popsicle sticks. Then repeat the layers until the molds are filled to the top. Freeze until all the way frozen, about 4 to 6 hours.
Remove the popsicles from the molds. Once frozen, run the tips of the molds under lukewarm water to set the popsicles free. Wrap the popsicles individually in plastic wrap or zip-lock bags. Store in the freezer for up to 6 weeks.