Shake flour in Reynolds® Oven Bag; place bag in 13x9x2-inch or larger baking pan at least 2 inches deep. Pour 2/3 cup pasta sauce in a large bowl; set aside. Add remaining pasta sauce to bag; squeeze bag to blend in flour.
Add ground beef, bell pepper, bread crumbs, egg, Italian seasoning, salt and garlic powder to pasta sauce in bowl; mix until well blended. Use about 1/3 cup mixture to form each meatball. Place meatballs in an even layer in oven bag.
Close oven bag with nylon tie; cut six 1/2-inch slits in top. Tuck ends of bag in pan.
Bake 30 to 35 minutes or until meat thermometer reads 160°F. Serve meatballs and sauce over hot cooked pasta OR cut meatballs in half and serve on hoagie rolls as meatball subs. Sprinkle shredded Parmesan cheese over meatballs, if desired.