01 - Bring a large pot of salted water to a rolling boil. Add pasta and cook according to package directions until al dente. Reserve 1/2 cup of starchy pasta water before draining in a colander. Set drained pasta aside.
02 - While the pasta cooks, heat a large skillet over medium-high heat. Add ground beef, season with salt and black pepper, and cook until fully browned and no pink remains, breaking the meat apart with a wooden spoon. Drain any excess fat and transfer the beef to a plate.
03 - In the same skillet, melt the butter over medium heat. Add minced garlic, Italian seasoning, and crushed red pepper flakes if using. Sauté for about 1 minute, stirring frequently, until the garlic is fragrant. Do not let the garlic brown.
04 - Return the browned ground beef to the skillet. Add the drained pasta and toss everything together. Gradually stir in small amounts of the reserved pasta water until the sauce coats the pasta evenly.
05 - Sprinkle the grated Parmesan cheese over the pasta and toss until melted and evenly distributed. Taste and adjust seasoning with additional salt and pepper as needed.
06 - Remove the skillet from heat. Garnish with chopped fresh parsley and serve immediately while hot.