Combine sugar and water in a small saucepan and bring to a boil over medium heat, stirring constantly. Once the sugar has dissolved, turn off the heat, and allow the syrup to cool.

With a food processor or high-powered blender, combine peeled and sliced peaches and raspberries together and puree. Add in 1 cup of water, and blend until smooth.

Strain the puree mixture through a fine mesh strainer in order to remove all seeds.

In a large pitcher, stir together simple syrup, raspberry peach puree, lemon juice, and 2 cups of water. (If the lemonade is too sweet, add in the remaining 1 cup of water.)

Enjoy immediately with ice, or allow to chill in the fridge until cool. Garnish with lemon wedges, raspberries, or peaches, if desired.