3 lb. (about 12 medium) potatoes, peeled, cooked and hot
1 (8 oz.) pkg. cream cheese, room temperature
1/4 c. butter
1/2 c. sour cream
1/2 c. milk
2 eggs, lightly beaten
1/2 c. onion, finely chopped (optional)
1 tsp. salt
Dash of pepper

In a large bowl, with mixer, mash potatoes, when lumps are gone, add cream cheese and butter in small pieces, beat well until completely mixed. Add sour cream, milk, eggs and onions together then add to potato mixture, beat until fluffy. Place in a greased 9-inch round casserole, refrigerate several hours, or overnight if not using them immediately.

Bake in preheated 350°F oven for 45 minutes or until slightly brown on top.

Serves 8 - 12. Great do ahead.