Prep: 2 minutes; Cook: 6 minutes
1. Preheat grill.
2. Brush both sides of chicken with barbecue sauce. Place chicken on grill rack coated with cooking spray. Grill 3 to 4 minutes on each side or until chicken is done, placing 1 cheese slice on each chicken breast during last minute of cooking.
3. Place lettuce and tomato on bottom half of each bun, if desired; add 1 chicken breast. Top each with about 2 1/2 tablespoons Spicy Avocado Spread. Place remaining bun halves on top.