Many versions of this Italian classic call for gratuitous amounts of heavy cream as a base for the sauce. I prefer to build the sauce with parmigiano, pecorino, and extra egg yolks. When blended with some of the starchy pasta water, this trio of ingredients creates a sauce that paradoxically is richer and creamier, with more depth of flavor than the cream-based version. To take it over the top, I double down on the pancetta, so that you get more crispy nuggets of cured pork belly with every twirl of the fork.