Creating Chicken Cordon Bleu Casserole is simple when you follow these easy steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking dish.
2. Mix Chicken and Ham: In a large bowl, combine the cooked chicken and diced ham.
3. Add Cheese: Stir in 1 ½ cups of shredded Swiss cheese into the chicken and ham mixture.
4. Prepare Sauce: In a separate bowl, mix together sour cream, mayonnaise, Dijon mustard, garlic powder, onion powder, salt, and black pepper until smooth.
5. Combine Ingredients: Pour the sauce over the chicken and ham mixture. Stir until everything is well coated.
6. Transfer to Baking Dish: Spread the mixture evenly in the prepared baking dish.
7. Top with Breadcrumbs: In a small bowl, combine breadcrumbs with olive oil. Sprinkle over the casserole.
8. Add Remaining Cheese: Top with the remaining ½ cup of shredded Swiss cheese.
9. Bake: Place the casserole in the oven and bake for 30-35 minutes or until bubbly and golden brown on top.
10. Cool Slightly: Remove from the oven and let it cool for a few minutes before serving.

These steps will guide you in creating a delicious Chicken Cordon Bleu Casserole that your family will rave about.