Cracker Barrel Hashbrown Casserole

Frozen shredded hash browns (32 oz)

Sour cream (16 oz)

Cream of chicken soup (1 can (10 1/4 oz))

Butter (melted, 1/2 cup)

Frozen diced onions (1/2 cup)

Shredded colby cheese (2 1/2 cups (divided))

Pepper (1/4 tsp)