Creating a delicious Chicken Cordon Bleu Casserole is straightforward when you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).

2. Prepare the Casserole Dish: Grease a 9×13-inch casserole dish with cooking spray or butter.

3. Mix Chicken and Ham: In a large bowl, combine the cooked chicken and diced ham.

4. Add Cheese: Gently fold in 1 cup of the shredded Swiss cheese with the chicken and ham mixture.

5. Mix the Sauce: In another bowl, whisk together the sour cream, chicken broth, Dijon mustard, garlic powder, onion powder, salt, and black pepper until well blended.

6. Combine Ingredients: Pour the sauce over the chicken and ham mixture, mixing thoroughly until everything is evenly coated.

7. Transfer to Dish: Spread the mixture evenly in the greased casserole dish.

8. Prepare Topping: In a small bowl, combine the remaining ½ cup of Swiss cheese with the bread crumbs and melted butter. Mix until well combined.

9. Top the Casserole: Sprinkle the bread crumb mixture evenly over the chicken mixture in the casserole dish.

10. Bake: Bake in the preheated oven for 30-35 minutes, or until bubbly and the top is golden brown.

11. Cool Slightly: Allow the casserole to cool for about 5 minutes before serving.