"This is a great casserole--not too sweet. I've adapted it from several other recipes. I usually double this for Thanksgiving. To make lighter version replace the eggnog with skim milk and use reduced calorie margarine."
1Preheat the oven to 350 degrees F (175 degrees C). Coat one 2 quart baking dish with non-stick cooking spray.
2Combine the mashed sweet potatoes, 1/3 cup brown sugar, eggnog, melted margarine, vanilla extract, salt and egg whites. Spoon mixture into the prepared baking dish.
3Combine the 1/2 cup brown sugar and flour. Cut in the chilled 2 tablespoons margarine until the mixture resembles coarse crumbs. Sprinkle over the sweet potato mixture.
4Bake at 350 degrees F (175 degrees C) for 30 minutes.