Place a large pot of water on the stove to boil. When water is rolling, add salt and pasta and cook to al dente, about 8 minutes, reserving 1/4 cup pasta water.
While pasta cooks, heat large skillet over moderate heat. Saute pancetta in a drizzle of oil until it browns, 3 to 5 minutes. Add extra-virgin olive oil, garlic, and crushed pepper flake. Saute garlic 2 minutes. Add wine or stock to the pan and reduce liquid by half, 2 minutes.
Beat together egg yolks, cheese, and while whisking vigorously, stir in a ladle of the boiling pasta water. Beat in parsley and pepper and set aside.
Drain pasta. Add pasta to pan with sauce. Toss pasta with pancetta, then add egg mixture and toss 1 minute, then remove from heat. Continue to toss until sauce is absorbed by and thickly coating the pasta. Adjust seasonings with salt and pepper and serve with extra cheese, for passing.