Bring a large pot of salted water to the boil and cook the spaghetti until al dente. Reserve 1 cup of pasta water, then drain.

Meanwhile, fry the guanciale in a large pan over medium heat until crisp and golden. Remove from heat.

In a bowl, whisk the egg yolks, whole eggs, and most of the Pecorino. Season with plenty of black pepper.

Add the hot pasta to the pan with the guanciale. Off the heat, quickly toss in the egg mixture and a splash of reserved pasta water. The residual heat will form a silky sauce. Add more pasta water if needed.

Serve immediately with the remaining Pecorino and extra black pepper.