Classic Make-Ahead Mashed Potatoes Recipe, Prep Time: 40-minutes , Serves: 12-servings, Directions: 1. Place potatoes in a Dutch oven and cover with water. Bring to a boil. Reduce heat; cover and cook for 15-20 minutes or until tender. Drain.  2. In a large bowl, mash potatoes with cream cheese. Combine the egg whites, sour cream, onion powder, salt and pepper; stir into potatoes until blended. Transfer to a greased 3-qt. baking dish.   3. Drizzle with butter. Cover and refrigerate…