How to Make It
In a large, deep skillet, cook the bacon over moderately low heat until crisp, 7 minutes.
In a large pot of boiling salted water, cook the fettuccine until almost al dente. Meanwhile, in a bowl, whisk the 1 cup of grated cheese with the egg, egg yolks and pepper. Carefully measure out 1 1/4 cups of the pasta cooking water and gradually whisk it into the egg mixture. Add the spinach to the fettuccine, then drain immediately.
Reheat the bacon in the skillet. Off the heat, add the fettuccine and spinach. Slowly pour in the egg mixture, tossing constantly with tongs. Set the skillet over moderate heat for a few seconds to warm the sauce; do not boil. Season lightly with salt and serve at once.