Preheat the oven to 350°F and grease a 13x9-inch pan.
In the prepared pan, mix the drained pasta, chicken, Alfredo sauce, sour cream, milk, and ranch dressing. Stir to combine. Add ¾ cup of cheese, half of the bacon bits, and mix gently.
Top with the remaining cheese and bacon bits and bake uncovered for 20 to 25 minutes or until hot.
Notes
Refrigerate any leftovers for up to 3 days.
Reheat portions in the microwave, or cover casserole with foil and heat in the oven at 300˚F until warmed. Or reheat on the stovetop with a little milk added to loosen up the sauce.