Au Gratin Crockpot Potatoes

1 32 ounce package frozen hash brown potatoes, partly thawed
2 10 ounce cans cheddar cheese soup, undiluted
1 13 ounce can evaporated milk, undiluted
1 3 ounce can French fried onion rings, divided
salt and pepper to taste

Spray inside of crockpot with cooking spray.

Add potatoes, soup, milk and onion rings, reserving 1/4 cup of the onion rings.

Add salt and pepper to taste, stir a little to combine.

Cover and cook on low for 7 to 9 hours or high about 3 hours.

Sprinkle reserved onion rings over top just before serving.