Cheesy Potato Casserole-Arlene

5 potatoes, peeled, cooked and mashed

1 cup sour cream

1 (8oz) package cream cheese, softened

1 1/2 cups shredded Cheddar cheese

3 tablespoons butter

Combine the first 3 ingredients. Add 1 cup cheese, butter, salt and pepper to taste. Place in greased casserole dish. Top with1/2 cup cheese. Cover. Bake at 350 degrees for 30 minutes. Excellent. Can be made ahead. Double recipe for more people.