Cook fettuccine in a large pot of boiling, generously salted water according to package directions until al dente.
Drain the pasta, returning it to the hot pot to keep warm.
While the pasta cooks, melt the butter in a large saucepan over medium heat.
Pour in the whipping cream, salt, and pepper.
Bring to a gentle boil, then reduce the heat to a simmer.
Let the sauce simmer for 3-5 minutes, stirring occasionally, until it has thickened slightly.
Remove the pan from the heat.
Stir in the 1/2 cup (480 ml) of grated Parmesan cheese until it has completely melted and the sauce is velvety smooth.
Add the warm pasta directly to the sauce.
Toss gently with tongs until every strand is coated in the creamy sauce.
Serve immediately with an optional sprinkle of extra Parmesan.
Reserve about a cup of the starchy pasta water before draining. It's liquid gold for thinning the sauce to the perfect consistency if it becomes too thick after tossing with the pasta.
Do not overheat the sauce after adding the cheese. Removing the pan from the heat before stirring in the Parmesan is the secret to a silky-smooth, non-greasy finish.