Place the 2 peaches, lemon juice and sugar in a blender and pulse until smooth. Divide into popsicle molds, placing about 2 tbsp in each mold.
Fill the molds the rest of the way with prosecco and add peach slices. Insert popsicle sticks and place in the freezer until frozen, 3-4 hours.
Unmold the popsicles by running the popsicle mold under warm water – make sure not to get water INTO the mold!
To store, wrap each popsicle in wax paper and place them in a freezer bag. Store in the freezer and enjoy whenever you like!