1. Bring a large pot of salted water to a boil. Add the rotini and cook until al dente. Drain and set aside without rinsing.

2. In a large skillet over medium-high heat, cook the ground beef until it begins to brown. Add diced onion, salt, pepper, and Italian seasoning. Cook until the beef is fully browned and onion is soft. Drain excess grease.

3. Lower the heat to medium and stir in minced garlic. Cook for 30 seconds until fragrant.

4. Push beef to one side of the skillet. In the empty space, melt the butter, then whisk in the flour to form a roux. Cook for 1–2 minutes.

5. Slowly pour in the warm milk and cream while whisking constantly. Let the mixture thicken for 3–5 minutes.

6. Stir in grated parmesan, garlic powder, and red pepper flakes. Mix until cheese is melted and the sauce is smooth.

7. Add the cooked pasta to the sauce, and stir everything together until evenly coated.

8. Serve hot, garnished with extra parmesan and parsley.