Gather all ingredients.
Preheat the oven to 350 degrees F (175 degrees C). Spray a 9x13-inch dish with nonstick cooking spray.
Gently mix potatoes, soup, cheese, onion, butter, salt, and pepper in a large bowl. Pour into the prepared dish.
Bake in the preheated oven until browned, about 1 hour.
Serve and enjoy!
