Bring a large pot of water to a boil. Add a pinch of salt and the spaghetti. Cook until al dente, about 8 minutes.

While the pasta cooks, heat a skillet over medium heat. Add the diced guanciale and cook until crispy, about 5 minutes. Remove from heat.

In a mixing bowl, whisk together the eggs, Parmesan cheese, and black pepper.

Drain the pasta, reserving 1/2 cup of the pasta water. Add the hot pasta to the bowl with the egg mixture.

Quickly toss the pasta with the egg mixture, adding a little reserved pasta water if needed to create a creamy sauce.

Add the crispy guanciale and toss everything together.

Serve immediately, garnished with additional Parmesan if desired.