In a large pot, combine the uncooked penne pasta, water, heavy cream, minced garlic, salt, black pepper, and dried Italian seasoning.
Place the pot over medium-high heat and bring the mixture to a boil, stirring occasionally to prevent the pasta from sticking.
Once boiling, reduce the heat to medium and continue to cook, stirring frequently, until the pasta is tender and most of the liquid has been absorbed, about 10 to 12 minutes.
Remove the pot from heat and stir in the unsalted butter and grated Parmesan cheese until the sauce is creamy and well combined.
Taste and adjust seasoning with additional salt and pepper if desired.
Serve immediately, garnished with extra Parmesan cheese if preferred.