01 - Bring a large pot of salted water to a boil. Cook pasta according to package directions until al dente. Reserve ½ cup of pasta cooking water, then drain the pasta.
02 - While the pasta cooks, melt butter in a large skillet over medium heat. Add minced garlic and sauté for 1 minute until fragrant, avoiding browning.
03 - Pour heavy cream and milk into the skillet. Bring the mixture to a gentle simmer while stirring continuously.
04 - Stir in grated Parmesan, salt, freshly ground black pepper, and nutmeg if using. Cook for 2 to 3 minutes until the sauce thickens slightly.
05 - Add the drained pasta to the sauce, tossing well to coat. If the sauce is too thick, loosen it by adding reserved pasta water a little at a time until desired consistency is achieved.
06 - Remove from heat. Sprinkle with chopped parsley and additional Parmesan cheese. Serve immediately.