Bring a pot of salted water to a rolling boil and cook the egg noodles according to the package directions. Drain and set aside once tender but firm, typically around 8-10 minutes.

In a large skillet over medium heat, add the ground beef. Cook until fully browned, breaking it apart with a spatula for even cooking, about 6-8 minutes. Drain any excess fat.

In the same skillet, melt the butter until foamy. Whisk in the flour, stirring constantly for about 2 minutes, until bubbly and golden, creating a roux.

Slowly add the beef broth to the roux, continuously whisking to avoid lumps. Cook until the mixture thickens, about 3-4 minutes.

Gently mix in the milk, whisking continuously to create a creamy consistency. Allow it to thicken further, which should take about 5-7 minutes.

Add in the garlic powder, onion powder, salt, and pepper, stirring well.

Add the drained egg noodles and cooked ground beef to the skillet, stirring well to coat the noodles in the sauce. Heat everything through for about 2-3 minutes.

Remove from heat and gently fold in the sour cream until well combined. Serve immediately.