Brown the Beef:
In a large skillet, cook ground beef with diced onion and garlic over medium heat until browned. Drain excess grease and transfer to the crockpot.
Add Base Ingredients:
Add the cream of mushroom soup, cream of chicken soup, beef broth, onion powder, garlic powder, salt, and pepper. Stir until well mixed.
Slow Cook:
Cover and cook on Low for 4–5 hours or High for 2–3 hours.
Add Noodles:
About 30 minutes before serving, stir in the uncooked egg noodles. Cover and cook on High until noodles are tender (about 25–30 minutes).
Add Cheese:
Stir in shredded cheddar cheese and butter until melted and creamy. If desired, mix in sour cream before serving.
Serve:
Spoon into bowls and enjoy warm!