Remove any rind from the guanciale or bacon and cut it into cubes or strips about 1 cm thick. Heat a pan over medium heat and add the guanciale. Fry for about 5 minutes, stirring occasionally, until the guanciale is crispy and the fat has melted. Be careful not to burn it. Optionally, you can add a small amount of extra virgin olive oil if desired. Season with a little salt and freshly ground black pepper once cooked, then set aside. I like to use guanciale for its authentic flavor, but bacon also works well in a pinch.

Bring a large saucepan of water to a boil. Once boiling, add salt generously, then add the spaghetti. Cook until the spaghetti is al dente, following the time on the package as a guide. When the pasta is almost done, reserve at least one cup of the boiling pasta water for later use before draining.

While the pasta is cooking, combine the grated Pecorino Romano cheese with the egg yolks in a bowl. Add the egg yolks one at a time, mixing continuously to form a creamy paste. Season the mixture with freshly ground black pepper. For a more authentic taste, I recommend using Pecorino Romano, but Parmesan or Grana Padano will do if that's what you have.

Transfer the drained spaghetti (from Step 2) to the pan with the cooked guanciale (from Step 1). Toss everything briefly over medium-low heat to distribute the rendered fat and flavor the pasta. Mix well using a wooden spoon. This step ensures the pasta absorbs all the delicious flavors from the guanciale.

Remove the pan from the heat. Immediately add the egg yolk and cheese mixture (from Step 3) to the hot pasta and guanciale (from Step 4). Stir rapidly to ensure the eggs gently cook with the residual heat and form a creamy sauce without scrambling. Gradually add some reserved pasta water as needed to adjust the sauce’s consistency until it's silky and coats the pasta well. I like to add just enough pasta water to make the sauce luxuriously creamy.

Plate the spaghetti carbonara immediately. Top with extra grated Pecorino Romano cheese and additional cracked black pepper to taste. Serve right away—carbonara is best enjoyed hot and fresh! I like to finish with a generous sprinkling of black pepper for a bit of heat.