Preheat your oven to 350°F (175°C).
In a large bowl, mix together the shredded chicken, sour cream, cream of chicken soup, cheddar cheese, garlic powder, salt, and pepper until well combined.
Spread the mixture evenly in a greased 9x13-inch baking dish.
In a separate bowl, combine the crushed Ritz crackers with the melted butter.
Sprinkle the cracker mixture over the casserole.
Bake for 30-35 minutes or until hot and bubbly and the top is golden brown.
Serve warm. Try not to eat it straight out of the pan—I dare you.