Bring a large pot of water to a boil

In a small bowl, whisk together the eggs, yolks, Pecorino Romano and Parmesan. Season with salt and freshly cracked black pepper.

Meanwhile, heat oil in a large skillet over medium heat, add the pancetta, and sauté until the fat just renders, and it's crispy. Remove from heat and set aside.

Cook the spaghetti until al dente. Just before pasta is ready, reheat pancetta in skillet. Reserve 1 cup of pasta water, then drain pasta and add to the skillet over low heat. Stir for a minute or so. Stir in cheese mixture, adding some reserved pasta water if needed for creaminess. Serve immediately, garnishing with a bit of additional grated pecorino and pepper.