1. Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions. Drain and reserve about 1 cup of pasta water.
2. Meanwhile, in a large skillet cook pancetta over medium heat until slightly crispy; set aside with all the drippings.
3. While the pancetta is cooking, in a medium bowl, whisk the eggs and yolks with Parmigiano-Reggiano, parsley and generous amount of salt and pepper to taste. After draining the pasta, return it to the pot and add the pancetta and drippings. Working quickly, add the egg and cheese mixture stirring everything together until the noodles are coated and creamy. Add pasta water, as needed, to loosen the noodles slightly if the sauce becomes too thick. Season with additional salt and pepper, if desired. Transfer to serving bowls and serve hot with additional cheese.