Refrigerator Mashed Potatoes

5 lbs. potatoes (9 large)
2 (3 oz) pkgs. cream cheese
1 cup dairy sour cream
2 tsp. onion salt
1 tsp. salt
1/4 tsp. pepper
2 tblsp. butter or margarine

Cook peeled potatoes in boiling salted water until tender. Drain.

Mash until smooth (no lumps). Add remaining ingredients and beat until light and fluffy. Cool.

Cover and place in refrigerator. May be used any time within two weeks.

To use, place desired amount in greased casserole, dot with butter and bake in moderate oven (350F) until heated through, about 30 minutes.

**** I've never made this recipe but it's my grandmothers. She makes a huge batch and freezes it to pull out when company comes. It's yummy.