Wash the peaches. Cut each peach in half around the crease to the stone. Twist halves in opposite directions to separate them. Remove stones with a teaspoon.
Slice flesh into a serving bowl. Combine sugar and cinnamon in a small bowl. Sprinkle peaches with rosewater and cinnamon sugar and combine gently. Cover with plastic wrap and chill.
Stir gently and garnish with fresh mint leaves just before serving.