Spaghetti with Pancetta, Eggs, and Cheese

1 pound spaghetti (450 g)
8 ounces pancetta, sliced about 1/ 4 inch thick and cut crosswise into thin strips (225 g)
2 whole eggs
2 egg yolks
3 tablespoons heavy cream
1/ 4 cup freshly grated pecorino Romano cheese (25 g)
2 tablespoons freshly grated Parmesan cheese
Salt and freshly ground black pepper

Bring a large pot of salted water to a boil. Add the pasta and cook until it is barely al dente.
While the pasta is cooking, in a large, deep skillet or flameproof casserole, cook the pancetta over moderate heat until it is golden, 4 to 5 minutes.
In a small bowl, beat together the whole eggs, egg yolks, cream, pecorino Romano, and Parmesan cheese. Season with salt and a generous grinding of pepper
Drain the spaghetti and add to the skillet with the pancetta with its rendered fat, mixing thoroughly. Pour the egg mixture over the pasta and toss rapidly over the lowest heat to coat evenly. Remove from the heat as soon as the egg begins to thicken. Continue tossing to mix well, adding another grinding of black pepper.
Serve at once in a heated dish with extra cheese and a pepper mill on the side.
NOTE: If you wish to make this dish for fewer or for more people, it is helpful to know that the general proportion for carbonara per person is usually 1¡¿¤ to 2 ounces (40 to 55 g) pancetta, 1 egg, 1 tablespoon pecorino Romano cheese, and 1 tablespoon Parmesan. When the number of servings is increased, I like to use some whole egg and some egg yolk, to keep the sauce rich and silky