1. Preheat oven to 350 degrees F. 2. Spray a 9x13 pan with cooking spray. 3. In a large bowl, combine cooked and shredded chicken, salsa, black beans, corn, cumin and chili powder. Stir until evenly mixed. 4. Layer 2 tortillas on the bottom of greased pan. NOTE: You may need to trim 1 tortilla to fit the gaps left by the two tortillas on each level. 5. Place half of the chicken mixture on top of tortillas and evenly spread across. 6. Sprinkle about 1/2-2/3 cup shredded cheese (about 1/3 of the bag)over chicken mixture. 7. Next pour 1/3 of enchilada sauce evenly over cheese. 8. Repeat layers of tortilla, chicken mixture, cheese and enchilada sauce then top with one last layer of tortillas. Evenly spread remaining enchilada sauce over the top level of tortillas. 9. In a small bowl, combine sour cream and can cream of chicken soup. Stir together completely. Evenly spread over the top tortilla layer. 10. Sprinkle with remaining cheese. 11. Cover with foil and bake at 350 degrees F for 35 minutes covered, then remove foil and bake for an addition 10 minutes or until cheese is completely melted and casserole is heated through.