Heads up: you'll need to save some pasta water before draining. Grate block of Parmesan cheese on a microplane (very important) and measure then set aside.Bring a large pot with 12 cups of water to a boil. Once boiling, add 1 tablespoon fine sea salt. Add the fettuccine and cook, stirring occasionally, until al dente according to package directions (use the lowest time listed). Before draining, reserve 1 cup of pasta water. Drain the pasta but do not rinse.

While the pasta cooks, melt the butter in a very large skillet or heavy pot over medium-high heat. Add onion powder and garlic powder. Cook for 30 seconds, stirring constantly, until fragrant. Pour in the cream, Italian seasoning, and salt and pepper (about ¼ teaspoon each).

When the mixture reaches a gentle boil, reduce heat to medium-low. Simmer for 1–3 minutes, until the sauce thickens enough to coat the back of a spoon (see note 3).

Remove the pan from the heat. Stir in the grated Parmesan, a small handful at a time, until melted and mostly smooth.

Add the drained pasta to the sauce along with ½ cup of the reserved pasta water. Return the pan to medium heat. Toss gently with tongs for about 1 minute, until the sauce turns silky and coats the pasta. Add more pasta water as needed to loosen the sauce (see note 4).

Remove from heat and serve right away. Garnish with parsley and extra Parmesan and pepper if desired.