Cook spaghetti in salted boiling water until al dente. Reserve 1 cup pasta water and drain.
In a skillet, cook pancetta over medium heat until crisp. Remove from heat.
In a bowl, whisk eggs with grated cheese and a generous amount of black pepper.
Add hot pasta to the pancetta skillet and toss to coat.
Remove from heat and quickly stir in egg mixture, adding reserved pasta water as needed to create a creamy sauce.
Serve immediately with extra cheese and black pepper.