Add peaches, prosecco, and simple syrup to a blender. Puree until smooth.
Divide raspberries evenly between popsicle molds. Be sure to push the large berries to the bottom so they stack up in the molds.
Top each with the prosecco mixture until full.
Add popsicle sticks and freeze for 4 to 6 hours, or until the popsicles are solid.