**Preheat the Oven:** Preheat your oven to 350°F (175°C) and grease a 9x13-inch casserole dish.
**Prepare the Casserole Mixture:** In a large mixing bowl, combine the cream of chicken soup, sour cream, chicken broth, garlic powder, onion powder, and black pepper. Mix until smooth.
**Add the Chicken:** Stir in the shredded or diced chicken until well coated with the creamy mixture.
**Assemble the Casserole:** Spread the chicken mixture evenly into the prepared casserole dish.
**Make the Topping:** In a separate bowl, mix the crushed Ritz crackers with the melted butter until combined.
**Top the Casserole:** Sprinkle the buttery cracker topping evenly over the chicken mixture.
**Bake:** Place the casserole in the preheated oven and bake for 30-35 minutes, or until the topping is golden brown and the casserole is bubbling.
**Serve:** Remove from the oven and let cool for 5 minutes before serving.