Step 1: Bring a large pot of salted water to a boil. Add the rotini pasta and cook until just al dente, about 9 to 11 minutes, depending on your package. Drain the pasta well and set it aside to keep warm.

Step 2: While the pasta cooks, heat the olive oil in a heavy-bottomed skillet over medium heat. Add the ground beef, breaking it up with a wooden spoon. Sprinkle in the Italian seasoning, garlic powder, salt, and black pepper. Cook until the beef is fully browned and caramelized, about 7 to 9 minutes. Once done, transfer the beef to a plate and set aside.

Step 3: In the same skillet, melt the unsalted butter over medium heat. Add the minced garlic and sauté for 1 to 2 minutes, stirring frequently until the garlic is fragrant and lightly golden but not burned.

Step 4: Pour in the beef broth and heavy cream while whisking constantly to combine and prevent lumps. Bring the mixture to a gentle simmer and cook for 3 to 5 minutes until the sauce thickens slightly.

Step 5: Lower the heat and whisk in the grated Parmesan and shredded mozzarella cheese. Stir continuously until the cheeses melt completely and the sauce is silky and smooth. Taste and adjust seasoning with salt and pepper as needed.

Step 6: Return the browned ground beef to the skillet, followed by the drained rotini pasta. Toss gently but thoroughly so every piece of pasta is coated in the luscious garlic butter sauce with tender beef bits.