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

Prepare the casserole dish: Grease a 9x13-inch baking dish with cooking spray or butter.

Mix the casserole ingredients: In a large bowl, combine the shredded chicken, cream of chicken soup, sour cream, cheddar cheese, garlic powder, and onion powder. Stir until everything is well combined. Add salt and pepper to taste.

Assemble the casserole: Pour the mixture into the prepared baking dish and spread it evenly.

Prepare the topping: In a small bowl, mix the crushed crackers with melted butter. Sprinkle this mixture evenly over the casserole.

Bake: Place the casserole in the preheated oven and bake for 25-30 minutes, or until the topping is golden brown and the casserole is bubbly.

Serve: Let the casserole cool for a few minutes before serving.