- 1½ sticks (¾ cup) unsalted butter, at room temperature for at least 30 minutes
- 1 cup freshly grated Parmigiano-Reggiano, plus more for serving (optional)
- 1 pound fresh fettuccine
- Salt
- In a large bowl with an electric mixer, beat the butter with the cheese until it forms a smooth cream, about 2 minutes.
- Bring at least 4 quarts of water to a boil. Add the pasta and salt to taste. Stir well. Cook over high heat, stirring frequently, until the pasta is al dente, tender yet still firm to the bite. Drain the pasta, reserving a little of the cooking water. Toss the pasta with the butter and cheese and a few tablespoons of the cooking water.
- Serve immediately with additional cheese, if desired.