Cheesy hash brown casserole bakes shredded potatoes in a creamy, cheesy sauce with a crispy cornflake topping. This vegetarian family favorite is a brunch staple and holiday side that everyone fights over.
Preheat your oven to 350°F (175°C) and lightly grease a 9x13-inch baking dish.
In a large mixing bowl, combine the thawed hash browns, shredded cheddar cheese, sour cream, condensed mushroom soup, melted butter, chopped onion, salt, and black pepper. Mix gently to avoid breaking up the potatoes.
Spread the hash brown mixture evenly into the prepared baking dish, pressing gently to distribute it uniformly.
Top the casserole with an even layer of crushed cornflakes for a crispy texture.
Bake uncovered for 50–55 minutes, until bubbling and the top is golden brown. Let it cool for at least 10 minutes before serving for optimal slicing.