Melt butter in large skillet over medium heat. Add brown sugar, and stir to blend. Add vanilla, cardamom, and nutmeg, and stir one minute. Add peach or nectarine slices, and toss gently to coat. Cook until sugar mixture melts and peach/nectarine slices are tender, about 5 minutes. Place scoops of ice cream in bowls; spoon peach mixture over ice cream, and garnish with nuts. 8 servings.
*The fruit can be sautéed up to 8 hours ahead - warm before serving.