In a large nonstick skillet, cook beef over medium heat until no longer pink; drain. Stir in the beans, corn, jalapeno, taco seasoning and ¾ cup tomato sauce.
Combine salsa and remaining tomato sauce. Spread ¼ cup into a 13-in. x 9-in. baking dish coated with cooking spray. Layer with four noodles (noodles will overlap slightly), half of the meat sauce, 1 cup salsa mixture, ½ cup Monterey Jack cheese and ½ cup cheddar cheese. Repeat layers. Top with the remaining noodles, salsa mixture and cheeses.
Cover and bake at 350° for 45-50 minutes or until edges are bubbly and cheese is melted. Let stand for 10 minutes before cutting. Serve with sour cream, avocado and onions.
