Sweet Potato Casserole

3 cup mashed cooked sweet potatoes (about 2 ¼ pounds)
1/3 cup firmly packed brown sugar
1/3 cup skim milk
2 tbsp reduced calorie stick melted margarine
1 tsp vanilla
½ tsp salt
2 egg whites, lightly beaten
vegetable cooking spray
½ cup firmly packed brown sugar
¼ cup flour
2 tbsp chilled reduced-calorie stick margarine
1/3 cup chopped pecans

Combine the first seven ingredients in a bowl and stir well.

Spoon sweet potato mixture into an 8" square baking dish coated with cooking spray.

Combine ½ cup brown sugar and flour in a bowl, and cut in 2 tablespoons chilled margarine with a pastry blender or 2 knives until the mixture resembles coarse meal.

Stir in the chopped pecans, and sprinkle over the sweet potato mixture.

Bake at 350°F for 30 minutes.