Bring a large pot of salted water to a boil. Cook the penne until al dente according to the package directions.
Before draining the pasta, reserve ½ cup of the pasta cooking water.
Melt the butter in a large skillet over medium-low heat.
Add the minced garlic and cook for about 30 seconds until fragrant. Do not let it brown.
Pour in the heavy cream and cook over low heat until small bubbles appear around the edges. Do not let it boil.
Gradually stir in the grated Parmesan cheese until completely melted and smooth.
Season with black pepper, salt, and Italian seasoning if using.
Add the cooked penne and toss until every piece is coated with the sauce.
Stir in a little reserved pasta water if the sauce is too thick.
Garnish with fresh parsley and extra Parmesan before serving.