Preheat oven to 350 degrees F (175 degrees C). Grease a 13X9-inch baking pan with cooking spray or butter. Combine hash browns, sour cream, bacon, ranch mix, and 1 cup Cheddar cheese in a large bowl; stir until well mixed. Spread into baking pan; cover with aluminum foil. Bake in the preheated oven for 45 minutes. Remove foil; sprinkle remaining Cheddar cheese evenly across potatoes. Bake until cheese is bubble and lightly browned around the edges, about 15 minutes.