Preheat oven to 350°.
Combine the beef, breadcrumbs, and onion, 1 tablespoon barbecue sauce, and remaining ingredients except cooking spray in a large bowl.
Shape meat mixture into a 9 x 5-inch loaf on a broiler pan coated with cooking spray. Spread remaining barbecue sauce over top of meat loaf. Bake at 350° for 1 hour or until a thermometer registers 160°. Let stand 10 minutes. Cut loaf into 12 slices.