In a small bowl, toss raspberries with 1 tablespoon sugar or to taste and set aside. If raspberries do not release juices, press with the back of a spoon. In another bowl, toss peaches with remaining sugar and set aside.Allow fruit to rest for 15 minutes or until juices release.
To serve, place peaches at the bottom of serving dishes and scoop frozen yogurt on top.Spoon over raspberries and garnish with fresh mint.Serve immediately.