Bring a large pot of salted water to a boil.
Add fettuccine pasta and cook until al dente, about 8-10 minutes.
Melt butter in a large skillet over medium heat.
Add heavy cream to the skillet and stir to combine with the butter.
Simmer the cream mixture for 5 minutes, stirring occasionally.
Whisk in the grated Parmesan cheese until melted and smooth.
Season with salt and black pepper to taste.
Drain the pasta and add it to the skillet with the sauce.
Toss the pasta until evenly coated with the sauce.
Serve immediately, garnished with chopped parsley.