Take care of the guanciale. Cut the guanciale into strips or cubes if it is thick enough. Place it in a pan without adding oil, as it will release its own fat when heated. Cook over medium-low heat, stirring occasionally, until it is crispy on the outside but still tender inside. Remove the pieces of guanciale and set aside the rendered fat to use later in the sauce.

Boil the pasta. Bring plenty of water to a boil in a large pot and add salt in moderation, since the guanciale and cheeses provide their own saltiness. When the water is boiling, add the spaghetti and cook it al dente, following the package instructions (about 8–9 minutes). Before draining the pasta, reserve a ladle of the cooking water.

Prepare the egg and cheese cream. In a bowl, place the egg yolks and beat them lightly. Add the grated pecorino romano and grana padano, along with a generous amount of freshly ground black pepper. Mix well until you get a smooth cream. If you like, you can add a teaspoon of the guanciale fat to intensify the flavor.

Combine and achieve the perfect texture. Drain the pasta without leaving it completely dry and immediately add it to the bowl with the egg and cheese cream. Stir quickly to prevent the egg from curdling. If the mixture is too thick, add some of the reserved cooking water and continue stirring until it reaches a creamy and silky texture. To get the perfect consistency without the egg coagulating, you can place the bowl over the hot pot in a “reverse bain-marie.”

Final plating. Serve the pasta on flat plates. Sprinkle with extra grated pecorino on top and distribute the crispy guanciale pieces. Finish with an additional touch of freshly ground black pepper.