Preheat the oven. Preheat the oven to 375°F. Grease a 9 by 13 inch baking dish and set aside.
Cook the noodles. Boil the egg noodles according to package directions. Drain, rinse under cool water, and set aside.
Cook the chicken and onion. Using the same pot the noodles were cooked in, add the diced chicken, onion, and 1 tablespoon of butter. Cook over medium heat until the chicken is fully cooked and the onions are soft. Remove from the heat.
Make the sauce. Add the cheddar cheese, cream of chicken soup, milk, sour cream, garlic powder, onion powder, salt, and pepper to the pot. Stir until fully combined.
Combine and assemble. Stir in the frozen broccoli and cooked egg noodles. Mix well, then pour the mixture into a greased 9x13-inch baking dish.
Add the topping and bake. In a small bowl, mix the remaining 1 tablespoon melted butter with the crushed Ritz crackers. Spread evenly over the top of the casserole and bake at 375°F for 25 minutes.
Cool and serve. Remove from the oven and let cool for 5 minutes. Scoop and serve. Enjoy!
Notes
Topping Options: While the cracker topping can be omitted, the buttery saltiness of Ritz crackers pairs especially well with this casserole. Panko or breadcrumbs may also be used.
Broccoli Prep: Frozen broccoli may be chopped into smaller pieces or purchased pre chopped to save time.
Chicken Options: Shredded chicken works well and is a great use for leftover or meal prep chicken.
Make Ahead: Assemble the casserole up to 1 day in advance and store covered in the refrigerator before baking.
Storage: Store leftovers in an airtight container in the refrigerator for up to 5 days.