Begin by filling a large pot with water, generously adding salt for flavor, and bring it to a rolling boil over high heat.

Add your spaghetti or bucatini to the boiling water, stirring occasionally, and cook until al dente, about 8-10 minutes.

While the pasta cooks, heat a skillet over medium heat and add the diced pancetta along with smashed garlic cloves; sauté for 5-7 minutes until crispy.

In a mixing bowl, whisk together the whole eggs, egg yolks, and both cheeses until creamy, adding black pepper to taste.

Transfer the hot pasta into the skillet with the crispy pancetta, tossing quickly in the warm bacon fat.

Immediately pour the creamy egg mixture over the warm pasta, tossing quickly to ensure it gently cooks without scrambling.

Gradually add reserved pasta water, about a tablespoon at a time, until your desired sauce consistency is reached.

Taste and adjust the dish with more cheese or freshly ground black pepper as needed; garnish with parsley and serve immediately.