Bring a large pot of salted water to a boil. Add bucatini and cook until al dente, according to package instructions. Reserve 1 cup of pasta water, then drain the pasta.
While the pasta cooks, beat the eggs in a bowl. Mix in the grated Parmesan cheese and black pepper.
In a large skillet, cook the pancetta over medium heat until it's crispy and the fat has rendered, about 5 minutes.
Add the drained pasta to the skillet with the pancetta. Toss well to coat in the fat.
Remove the skillet from the heat. Quickly pour the egg and cheese mixture over the pasta, stirring vigorously to coat the pasta without cooking the eggs. If the sauce is too thick, add reserved pasta water, one tablespoon at a time, until desired consistency is reached.
Season with salt to taste and serve immediately, garnished with more Parmesan cheese, black pepper, and optional parsley.
Notes
Make sure to cook the pasta al dente since it will continue to cook slightly when mixed with the hot sauce.
• Reserve some pasta water to help thicken the sauce and help it cling to the noodles.
• Gradually mix the egg and cheese mixture into the pasta to avoid scrambling the eggs.
• Add the pancetta and its fat to the pasta for a richer flavor.
• Serve immediately while hot for the best texture and taste.