
Bring a large pot of salted water to a boil. Add the spaghetti and cook according to package directions until al dente. Reserve about 1 cup of the pasta water before draining.
While the pasta is cooking, dice the pancetta and cook in a large skillet over medium heat until crispy. Remove the pancetta from the skillet and set aside, reserving the rendered fat in the pan.
In a bowl, whisk together the eggs, egg yolks, Pecorino Romano cheese, and black pepper.
Drain the spaghetti and immediately add it to the skillet with the reserved pancetta fat. Toss to coat the pasta in the fat.
Remove the skillet from the heat. Quickly pour the egg mixture over the hot pasta, tossing constantly to prevent the eggs from scrambling. If the sauce is too thick, add a little of the reserved pasta water until it reaches your desired consistency.
Add the crispy pancetta to the pasta and toss to combine.
Serve immediately, garnished with extra Pecorino Romano cheese and freshly ground black pepper.