Spray a large 9 x 13-inch dish with cooking spray.
In a large bowl, combine all ingredients. Transfer to prepared baking dish, cover, and refrigerate at least 6 hours (or up to 24 hours). See note below if you don't have time to refrigerate in advance!
When you’re ready to bake the casserole: If you have the time, I like to pull the dish out of the refrigerator and allow it to sit on the counter and come to room temperature for about 30-60 minutes before I put it in the oven.
Bake, uncovered, at 350 degrees F for 1 hour (or until pasta is tender and chicken is cooked through).
