Pre-heat the oven to 350°F. Spray a 9x13-inch baking dish with cooking spray.
In a large bowl, combine the cooked chicken, black beans, corn, diced tomatoes with green chilies, sour cream, cream cheese, 1 cup of the shredded Mexican blend cheese, and taco seasoning. Stir until well combined.
Spread a layer of tortilla chips at the bottom of the prepared baking dish.
Pour half of the chicken mixture evenly over the layer of tortilla chips, spread out with the back of the spoon.
Add another layer of tortilla chips on top of the chicken mixture.
Pour the remaining chicken mixture over the second layer of tortilla chips, spreading it evenly.
Sprinkle the remaining tortilla chips and cheese over the top.
Bake in the pre-heated oven for 25-30 minutes, or until the cheese is melted and the casserole is heated through.
Allow the casserole to sit for 5 to10 minutes after it comes out of the oven before serving.