1 cup sugar
1 cup of water
3 large peaches
6 cups sparkling water
1 cup fresh-squeezed lemon juice
1 1/2 cup vodka
In a small pot, combine the sugar and 1 cup of water. Bring to a simmer over medium heat, and simmer until the sugar is dissolved. Remove from heat and cool completely.
Remove the skins from 2 of the peaches, reserving the third. Cut an "X" in the bottom of each one, and place them in a pot of boiling water for about 30 seconds. Transfer the peaches to an ice bath, and peel when cool enough to handle. Slice each peeled peach in half and remove the pits. Cut peaches into cubes, place them in the blender or food processor, and puree until liquified.
In a large pitcher, combine the pureed peaches, the cooled simple syrup, the sparkling water, the lemon juice and the vodka. Stir to combine. Add ice and stir again.
Cut the remaining peach into thin slices. Stir a few of the slices into the lemonade and use the others to garnish the glasses.