Spray the foil squares with cooking spray then arrange the potatoes on one side of each square.
Top the potatoes with the cooked and crumbled bacon.
Sprinkle each packet of potatoes with the ranch dressing mix and salt and pepper to taste.
Pat a tablespoon of butter on top of each packet of potatoes.
Double fold the edges of the aluminum foil to wrap each packet securely.
Grill or bake at 400 degrees for 20 to 30 minutes or until potatoes are cooked through. Serve in the foil packages.