Preheat oven to 350 degrees. Line a rimmed baking sheet with aluminum foil; place a wire rack on top of the sheet. Arrange the bacon in a single layer on the rack. Sprinkle the bacon evenly with the sugar or pepper. Tightly twist each slice to form a spiral. Bake until the bacon is crisp and browned, about 30 to 35 minutes. (For a sweeter alternative, replace the brown sugar and pepper with ½ cup sugar and 1 tablespoon cinnamon.)