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; gradually add milk mixture to saucepan, stirring with a whisk. Bring to a boil; cook 2 minutes or until thick. Remove from heat; let stand 4 minutes. Add 1 Cup Italian cheese blend, onion powder, garlic powder, dill, and salt, stirring until cheese melts. Stir in pasta, chicken, and bacon.
Spoon mixture in a 13 x 9 baking dish coated with cooking spray. Sprinkle evenly with remaining cheese. Broil 3-5 minutes until heated through and cheese is melted. (Doesn't take long if you cook your pasta while preparing your sauce mixture since the noodles will still be hot when you mix everything together)