Bring a big pot of salted water to boil and cook pasta according to the package but 1 minute shy of the recommended time.
While the water is boiling, whisk eggs and cheese together in a small bowl. Add a few turns of freshly ground pepper. Set aside.
Heat a skillet over medium-high heat. Add pancetta and cook until crispy, approximately 5-7 minutes. Stir frequently. Add garlic and cook for 1 minute, stirring.
Drain pasta, reserving 1 cup of pasta water (you will not use the whole amount) and place pasta into the skillet. Add the egg and cheese mixture and toss everything to combine. Work quickly through this step. Add reserved pasta water 1 tsp at a time until you reach the desired consistency. Add salt and pepper to taste.
Serve immediately and garnish with additional cheese and parsley if desired.