Mashed-Potato Rosettes

Put potatoes in water to cover in a large saucepan. Bring to boil over high heat. Cover; reduce heat to medium and cook 15 minutes until tender; drain well in colander. Return to pot or place in large bowl. Add butter, salt and pepper. Break up potatoes with potato masher or electric mixer. Add 1 egg; mash until smooth and well blended. Spoon into a pastry bag fitted with a large star tip. Lightly grease a cookie sheet. Pipe 16 mounds of potatoes on prepared sheet. Beat remaining egg in a small bowl. Brush over potatoes. (Can be refrigerated at this p