01 - Bring a large pot of salted water to a rolling boil. Add the penne and cook until al dente, approximately 10–12 minutes. Reserve 60 ml of the pasta cooking water, then drain and set pasta aside.
02 - In a large skillet set over medium heat, melt the butter. Add the minced garlic and cook, stirring, for about 30 seconds until aromatic.
03 - Reduce heat to medium-low. Pour in the heavy cream and milk. Season with salt, black pepper, red pepper flakes (if using), and Italian seasoning. Stir well and allow to simmer gently for 2–3 minutes.
04 - Add the grated Parmesan cheese gradually, stirring constantly to create a smooth sauce. If the sauce thickens excessively, add reserved pasta water in small amounts until reaching desired consistency.
05 - Add the drained penne to the skillet and toss thoroughly to coat each piece with the sauce. Allow the pasta to cook in the sauce for another 1–2 minutes to absorb the flavors.
06 - Remove from heat. Top with chopped fresh parsley, additional grated Parmesan, and a dash of freshly ground black pepper if desired. Serve immediately.