Pre-heat oven to 350°F.
Grease a 13 x 9-inch baking pan with cooking spray or butter.
In a large bowl, combine hash browns, sour cream, bacon, ranch mix, and 1 cup Cheddar cheese; stir until well mixed.
Spread into baking pan; cover with aluminum foil.
Bake in the pre-heated oven for 45 minutes.
Remove foil; sprinkle remaining cheddar cheese evenly across potatoes.
Return to oven and bake until cheese is bubble and lightly browned around the edges, about 15 minutes.