Preheat oven to 350 F degrees. Grease a 9x13 or 3 quart baking dish and set aside.
In a large mixing bowl, add ½ cup melted butter, sour cream, cream of chicken soup, salt, pepper, onion powder, garlic powder and smoked paprika. Stir well.
Add in thawed hash brown potatoes and the cheddar cheese and stir well to combine.
Transfer to prepared baking dish, and sprinkle with mozzarella cheese.
In a small mixing bowl, combine ¼ cup melted butter and cornflakes, stirring well. Spread evenly over the top of the casserole.
Bake uncovered, 45-50 minutes, until hot and bubbly and cornflakes are golden brown.
