Gather all ingredients and preheat the oven to 350 degrees F (175 degrees C).
Combine hash browns, Cheddar cheese, condensed soup, sour cream, ½ cup melted butter, onion, salt, and pepper in a large bowl.
Transfer mixture to a 3-quart casserole dish.
Sauté cornflakes and remaining ¼ cup melted butter in a saucepan over medium heat.
Sprinkle the mixture over the top of the casserole.
Cover casserole and bake in the preheated oven for 40 minutes.
Serve and enjoy!
