Gather all ingredients. Preheat the oven to 375 degrees F. Lightly grease a 9x13-inch baking dish with cooking spray.
Mix together hash browns, condensed soup, sour cream, Cheddar cheese, and ham in a bowl until well combined.
Spread evenly into the prepared dish. Sprinkle with Parmesan cheese.
Bake in the preheated oven until bubbly and lightly brown, about 1 hour.
