In a large skillet, slowly cook pancetta in olive oil until crisp. Remove pancetta with a slotted spoon, and reserve the oil. Keep pancetta warm in a 150° oven along with your dinner plates.
Cook spaghetti in boiling, salted water. While the spaghetti cooks, mix egg yolks together with Pecorino cheese in a serving bowl, and beat well with a whisk or fork. Add cooled oil from the skillet used to cook pancetta, along with 2 tablespoons hot pasta water and half of the cooked pancetta.
When spaghetti is al dente, drain, leaving some water clinging to the pasta – tongs work well for this. Add spaghetti to a skillet on medium heat with some pasta water, and toss well to get the pasta hot. Keep pasta water hot for later.
Turn off heat. Spoon egg and cheese mixture over pasta, and mix with tongs until ingredients are incorporated and hot. Add hot pasta water if you need more moisture and heat. Be careful not to let the eggs get too hot, or they will scramble.
Plate pasta on heated plates with a sprinkling of pancetta and freshly ground black pepper. Serve immediately.
