Instructions:
- Dice the guanciale into small cubes (about ½ inch). Place them in the cold, dry, heavy-bottomed skillet.
- Cook the pork gently over medium-low heat, stirring occasionally, until the fat is fully rendered and the pork pieces (Ciccioli) are crispy and golden brown.
- Remove the crispy guanciale pieces with a slotted spoon and set aside. Leave all rendered fat in the pan, removing the pan from the heat source entirely for now.
- Bring a large pot of water to a rolling boil. Salt the water lightly. Cook the spaghetti until very al dente (about 1–2 minutes less than package directions).
- While the pasta cooks, vigorously whisk the egg yolks, whole egg, finely grated Pecorino Romano, and black pepper together in a mixing bowl until a very thick, pale paste forms.
- Temper the base: Take 2 tablespoons of the hot rendered pork fat from the skillet and slowly drizzle it into the egg-cheese paste while whisking constantly to gently warm the eggs.
- Reserve at least 1 ½ cups of the starchy pasta cooking water. Using tongs, immediately transfer the al dente spaghetti directly into the skillet containing the remaining rendered fat. Toss quickly over very low heat for about 30 seconds to coat.
- Remove the skillet COMPLETELY from the heat source. Wait about 15 seconds for the pan temperature to drop slightly. Pour the tempered egg/cheese mixture over the pasta.
- Toss and stir the pasta rapidly using tongs. Gradually add small splashes of the reserved starchy pasta water, mixing continuously, until a glossy, thick, creamy sauce coats every strand. Do not place the pan back on the heat.
- Stir in most of the crispy guanciale. Serve immediately in warm bowls, topping each portion with the remaining crispy pork, a final grating of fresh Pecorino, and extra black pepper.