Boil salted water in large pot.
Cook spaghetti until al dente texture.
Dice pancetta into small uniform pieces.
Cook pancetta until golden and crispy.
Whisk eggs and egg yolks together.
Add grated cheeses to egg mixture.
Season with fresh black pepper generously.
Reserve one cup hot pasta water.
Drain pasta but keep it hot.
Remove pancetta pan from direct heat.
Add hot pasta to pancetta pan.
Toss pasta with rendered pancetta fat.
Slowly add egg mixture while tossing.
Add pasta water gradually for creaminess.
Toss continuously until sauce coats pasta.