Preheat the oven to 350 F. Lightly spray a 9 x 9-inch square baking dish with cooking spray.

In a medium bowl whisk together the sour cream, chicken broth, melted butter, garlic powder, chili powder, salt, and ground pepper until well combined.

Pour one-third of the sour cream sauce into the bottom of the baking dish. Layer 4 of the cut-up tortillas in the dish over the sauce. Top the tortillas with one-half of the chicken. Spoon about one-third of the diced tomatoes and green chilis mixture over the chicken, then top with about one-third of the cheese.

Repeat the layers with another one-third of the sauce, 4 tortillas, the remaining chicken, one-third of the tomato and chilis, and one-third of the cheese.

Add the remaining tortillas on top, followed by the remaining sauce, cheese and tomatoes and green chilis.

Cover with foil and then bake in the preheated oven for 15 minutes. Remove the foil and continue baking for another 20 to 30 minutes until it is hot and bubbly.

Cut and serve.