Preheat the oven. Set your oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish with butter or cooking spray.
Make the creamy base. In a large bowl, whisk together the cream of chicken soup, sour cream, and chicken broth (if using). Stir in garlic powder, onion powder, paprika, salt, and pepper.
Add the chicken and cheese. Fold in the cooked chicken and half of the shredded cheese.
Mix until everything is evenly coated.
Transfer to the dish. Spread the chicken mixture evenly in the prepared baking dish.
Crush the crackers. Place the Ritz crackers in a zip-top bag and crush them with your hands or a rolling pin. You want small pieces, not fine crumbs, for the best crunch.
Make the topping. In a bowl, combine the crushed crackers with the melted butter. Stir until all the pieces are lightly coated.
Top and bake. Sprinkle the cracker mixture evenly over the casserole.
Bake for 25–30 minutes, until the topping is golden and the edges are bubbling.
Add final cheese (optional). If you like a cheesy top, sprinkle the remaining cheese over the casserole in the last 5 minutes of baking.
Rest and serve. Let the casserole sit for 5–10 minutes before scooping. Garnish with chopped parsley. Serve warm.