Place sweet potatoes in a large saucepan or Dutch oven; cover with water. Bring to a boil. Reduce heat; cover and cook for 30-45 minutes or just until tender. Drain and cool slightly; peel and cut into cubes.
In a small bowl, combine the brown sugar, cashews, salt and ginger. Place half of the sweet potatoes in an ungreased 11x7-in. baking dish; top with half of the peaches and brown sugar mixture. Repeat layers; dot with butter.
Cover and bake at 350° for 30 minutes. Uncover; bake 10 minutes longer or until bubbly and heated through.