Preheat oven to 350°. In a large skillet, cook and crumble ground beef and onions until beef is thoroughly cooked. Drain off extra grease.
Add beans, corn, seasoning, jalapenos and enchilada sauce. Stir in; heat through for several minutes.
Spray cooking spray in a 9x13-inch baking dish. Set aside 1 cup of Fritos and spread the rest on the bottom of the dish. Layer the remaining ingredients over the Fritos: meat mixture, cheese, and top with more Fritos.
Bake, uncovered, 15-20 minutes or until cheese is melted. Sprinkle with jalapeno slices or desired toppings.