1In 4-quart saucepan or Dutch oven, place potatoes; add enough water just to cover potatoes. Heat to boiling. Reduce heat to low; cover and simmer 20 to 25 minutes or just until potatoes are tender. Drain; rinse with cold water to cool slightly.
2Heat oven to 350°F. Spray 2- to 2 1/2-quart shallow casserole with cooking spray. Remove skins from sweet potatoes. Cut into 1/2-inch slices; place in casserole.
3In 1-quart saucepan, heat brown sugar, cornstarch, salt, cinnamon, nutmeg, apple juice and 2 tablespoons butter to boiling over medium-high heat, stirring constantly. Boil and stir 1 minute. Pour mixture over potatoes. In small bowl, mix topping ingredients until crumbly. Sprinkle evenly over sweet potatoes.
4Bake uncovered 15 to 20 minutes or until bubbly.