Mashed Potaote Casserole

Mashed potatoes can sometimes be a bother when you have a meal that requires a lot of last minute attention. They are also hard to bring to someone's house when you are asked to bring the potato dish. This recipe solves both of these issues and if I may say myself is better than just plain mashed potatoes.
Do note that they are made the day before and refrigerated until baking time. It is also worthy to note that they travel well and hold the serving temperature well.

3 pounds of potatoes, boiled and mashed
8 oz. cream cheese, cut into pieces
1/4 cup butter, cut into pieces
1/2 cup sour cream
1/2 cup milk
2 eggs lightly beaten
1/4 cup finely chopped onions (I usually increase slightly)
1/2 teaspoon salt
dash of pepper

In a large bowl combine the mashed potatoes, cream cheese and butter until blended.
Add milk, eggs and onion to the mixture beating until fluffy.
Place mixture in a 9" x 9" baking dish and refrigerate several hours or over night.

Bake at 350 degrees until brown (45 minutes).