3/4 pound sweet potato, peeled and diced
1 (9 inch) refrigerated pie crust
3/4 cup evaporated skim milk
2 egg whites
1/4 cup white sugar
2 tablespoons brown sugar
3/4 teaspoon ground cinnamon
1/8 teaspoon ground nutmeg
1/8 teaspoon ground cloves
1/4 cup halved cranberries (optional)