Cook noodles according to package directions, omitting fat and salt. Drain pasta over a small bowl, reserving 1/2 cup cooking liquid.
Cook bacon in a large nonstick skillet over medium heat until crisp. Remove bacon; reserve 1 tablespoon drippings in skillet. Crumble bacon; set aside. Add red pepper and garlic to skillet; cook 30 seconds. Add spinach; cook 1 minute or until lightly wilted. Remove from heat. Add pasta, reserved cooking liquid, cheese, and salt. Toss gently.