Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   3      cups          sweet potatoes -- mashed
                        (about 2 1/4 pounds)
     1/3  cup           brown sugar -- packed
     1/3  cup           skim milk
   2      tablespoons   reduced-calorie margarine -- (stick)
   1      teaspoon      vanilla
     1/2  teaspoon      salt
   2                    egg whites -- lightly beaten
                        vegetable cooking spray
     1/2  cup           firmly packed brown sugar
     1/4  cup           flour
   2      tablespoons   reduced-calorie margarine
     1/3  cup           chopped pecans

Preparation:

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 1/2 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 350F for 30 minutes. Serving size = 1/2 cup.