Preheat oven to 350°F and grease a 9x13 baking dish.
Cook egg noodles in chicken broth until just tender; drain.
In a large bowl, mix cream of chicken soup, cream of mushroom soup, sour cream, and softened cream cheese until smooth.
Stir in onion (or onion powder), garlic powder, salt, and pepper.
Add cooked chicken and noodles; mix until evenly coated.
Pour mixture into prepared baking dish and spread evenly.
In a skillet, melt butter over medium heat. Add Ritz cracker crumbs and stir until coated and lightly toasted.
Sprinkle cracker topping evenly over casserole.
Bake uncovered for 30–40 minutes, until hot and bubbly and topping is golden.
Let rest 5–10 minutes before serving.