Preheat oven to 400ºF. Line a baking sheet with foil; place a baking rack on top. Mist rack with cooking spray. Arrange 12 slices of bacon on rack. Sprinkle on 1 to 1 1/2 Tbsp. pepper and dark brown sugar. Roast until bacon begins to brown, about 15 minutes. Remove sheet from oven. Place bacon on a paper towel-lined plate. Pour grease out of tray into a bowl. Repeat with 12 more slices of bacon, pepper and brown sugar. When bacon is cool, wrap in plastic wrap and chill overnight. Reheat in batches in microwave.