In a large pan, melt butter over medium heat until fully melted, then immediately turn off the heat.
In a large pot of salted boiling water, cook your fettuccine to al dente or until desired doneness.
2 minutes before the pasta is done, reserve a cup of pasta water and set aside to cool. Let the temperature of this water to be around 150F or 65C (use a thermometer for better accuracy).
Once the pasta is cooked to your desired doneness, immediately transfer to the butter and add ⅓ cup pasta water and your cheese.
Stir vigorously (still off the heat), adding pasta water as needed, until a creamy sauce is achieved.
Adjust seasoning for salt to your preference.
Serve immediately in a warm bowl with additional parmesan and optional freshly cracked black pepper and enjoy!
