Bring a large pot of salted water to a boil.
Add spaghetti and cook according to package instructions until al dente.
While pasta cooks, heat a pan over medium heat and add pancetta.
Cook pancetta until crispy, about 5-7 minutes.
In a bowl, whisk together eggs, Pecorino Romano, Parmesan, and pepper.
Reserve 1 cup of pasta water, then drain the spaghetti.
Quickly add hot spaghetti to the pancetta in the pan.
Remove from heat and pour the egg mixture over the pasta, stirring quickly.
Add reserved pasta water a little at a time until desired creaminess is achieved.
Serve immediately, topped with extra cheese and pepper.