Chicken cordon bleu casserole deconstructs the French classic into a creamy bake with chicken, ham, Swiss cheese, and a crispy breadcrumb topping. This high protein family dinner is elegant comfort food made easy.
Preheat the oven to 375°F and lightly grease a 9x13-inch baking dish to ensure even browning and prevent sticking.
In a medium saucepan over low-medium heat, melt butter, then whisk in cream cheese until smooth, followed by milk; cook until well blended and creamy but do not boil.
Stir in garlic powder, black pepper, salt, and dried parsley, cooking for 1 minute; remove from the heat and fold in half the Swiss cheese until melted.
Layer cooked chicken breast evenly in the prepared dish, then scatter diced ham atop; pour the cream cheese sauce over the entire mixture, spreading gently with a spatula.
Top with the remaining Swiss cheese and breadcrumbs; bake for 25–30 minutes, until the top is golden and the sauce is bubbling, then let rest for 5 minutes before serving to improve texture.