Preheat oven to 450 degrees. Line a 9 by 13-inch pan with foil and spray with vegetable oil. Place the chicken legs on top of the greased foil. Drizzle the olive oil over the meat. Or you can just spray vegetable spray on them. Sprinkle with salt and pepper. Bake for 25 minutes uncovered. After 25 minutes brush the BBQ sauce on the meat and return the pan to the oven. Cook for another 10-15 minutes or until the sauce starts to sizzle and look charred. Use a meat thermometer to ensure the thickest part of the leg is registering 160 to 165 degrees. It will go up about 5 degrees once you let the meat sit on the counter after baking for 5-6 minutes or so. The cooking time will depend on how big or small your chicken legs are.