Place short ribs, garlic, ginger and pepper flakes in a slow cooker. Pour KC Masterpiece(R) Hickory Brown Sugar Barbecue Sauce and broth over ribs. Cover and cook on high 4-5 hours or until meat is tender but not falling apart.
Remove meat; place on a cutting board. Strain cooking liquid into a large pot. Discard bones and fat, and slice meat into large cubes. Skim any fat from broth and add meat, celery, carrot and spinach. Simmer soup about 10 minutes or until vegetables are tender.
Place noodles in warm soup bowls, ladle hot soup over noodles and sprinkle with cilantro.