Cook ground beef, onion, and mushrooms in a large nonstick skillet over medium-high heat until browned, and stir to crumble.
Drain.
Combine beef mixture, macaroni, and next 6 ingredients (macaroni through soup) in a 2-quart casserole dish coated with cooking spray. Stir in 1/2 cup cheese; sprinkle 1/4 cup cheese over top.
Bake at 350 for 30 minutes or until bubbly.
Note: This dish reheats well. Store it in the refrigerator for up to 3 days or in the freezer for up to 1 month.