Bring a large pot of salted water to a boil and cook the spaghetti until just tender. Reserve 1 to 2 cups of pasta water before draining.

In a large pan over medium heat, cook the guanciale or pancetta slowly until the fat renders and the edges become golden. Remove from heat.

In a bowl, whisk together the whole eggs, yolks, most of the grated cheese, and a generous amount of black pepper until thick and gritty.

Add the drained spaghetti to the pan with the pork and toss to coat the pasta in the fat. Let it cool slightly for 20 to 30 seconds if the pan is very hot.

Quickly pour in the egg and cheese mixture while tossing continuously, allowing the residual heat to gently cook the eggs and create a creamy sauce.

Add a splash of reserved hot pasta water to loosen the sauce, adjusting to achieve a silky consistency while tasting for additional salt.

Serve immediately, topped with remaining cheese and more freshly cracked pepper.