Boil salted water in a large pot.
Add spaghetti and cook until al dente.
In a separate pan, cook pancetta until crispy.
Whisk together eggs and grated cheese in a bowl.
Drain spaghetti, reserving some pasta water.
Add hot spaghetti to the pan with pancetta.
Remove from heat and quickly mix in the egg mixture.
Add reserved pasta water as needed for creaminess.
Season with salt and pepper to taste.
Serve immediately with chopped parsley and extra cheese.