Place fettuccine in a pot of boiling water that’s been seasoned generously with salt. Cook until desired doneness.
In a large bowl, add softened unsalted butter and season with pepper.
Reserve ¾ cup of pasta water. Drain the pasta.
Immediately add pasta to the large bowl and toss with the butter vigorously.
Once butter is melted, add in grated parmigiano reggiano. Toss until combined using pasta water as needed to melt the cheese. Season with salt and pepper.
Serve in a bowl topped with additional parmigiano reggiano.