Spray 5-quart oval slow cooker with cooking spray.
In large bowl, mix chicken, cheese, soup, milk and taco seasoning mix.
Stir in green onion whites and jalapeño chiles.
Pour into slow cooker; spread evenly.
In medium bowl, mix cornbread & muffin mix, corn and egg.
Stir in melted butter.
Pour evenly over chicken mixture.
Place folded, clean dish towel under cover of cooker.
This will prevent condensation from dripping down onto cornbread.
Cover; cook on Low heat setting 3 to 4 hours or until instant-read thermometer inserted in center of mixture reads at least 165°F and toothpick inserted in center of cornbread comes out clean.