Cook pasta according to package directions, omitting salt and fat; drain.

Cook bacon in a large nonstick skillet over medium heat until crisp. Remove bacon from pan, reserving drippings in pan. Finely chop bacon; set aside. Increase heat to medium-high. Season chicken with onion powder, garlic powder and salt. Add chicken to drippings in pan; sauté 6 minutes or until done.

Melt butter in a large saucepan over medium heat; sprinkle flour evenly into pan. Cook 2 minutes, stirring constantly with a whisk. Combine milk and soup, stirring with a whisk; then gradually add milk mixture to saucepan, stirring with a whisk. Bring to a boil; cook 2 minutes or until thick. Add ranch dressing and 3/4 cups of cheese, stirring until cheese melts. Stir in pasta and chicken.

Preheat broiler.

Spoon pasta mixture into an 8-inch square baking dish coated with cooking spray. Sprinkle evenly with reserved bacon, fried onions and 1/2 cup of cheese. Broil 3 minutes or until cheese melts.