Preheat oven to 400. Spray bottom and side of 9-inch round or square baking pan with nonstick cooking spray.
Combine nectarines, blueberries, granulated sugar, cornstarch and cinnamon in medium bowl. Transfer to prepared pan; bake 15 minutes.
Meanwhile, combine remaining ingredients in small bowl, stirring with fork until crumbly. Remove fruit mixture from oven; sprinkle with topping. Bake 20 minutes longer or until fruit is bubbly and topping is lightly browned. Serve warm.