Place each chicken breast half between 2 sheets of heavy-duty plastic wrap; pound to 1/2-inch thickness using a meat mallet or rolling pin. Sprinkle chicken evenly with salt and pepper.
Cook bacon in a large nonstick skillet over medium heat until crisp. Remove bacon from pan. Add chicken to drippings in pan; cook 6 minutes on each side or until done. Remove chicken from pan; keep warm.
Add onion to pan; cook 2 minutes or until tender, stirring constantly. Add cider and broth; bring to a boil, scraping pan to loosen browned bits. Cook until broth mixture is reduced to 1/2 cup (about 5 minutes). Stir in cooked bacon; serve sauce over chicken.