Bring a large pot of salted water to a boil and cook the spaghetti according to packet directions until al dente. Reserve ¼ cup of pasta cooking water before draining.

While the pasta is cooking, heat a frying pan over medium heat. Add the diced bacon and cook until it becomes crispy and browned. Once done, remove the bacon from the pan and place on a plate with a paper towel to allow the excess fat to drain away.

In a large bowl, whisk the eggs and add the finely grated Parmigiano-Reggiano. Stir to combine, and season with black pepper. Add in the cooled bacon.

Once the spaghetti is cooked, transfer it to the bowl with the egg mixture immediately and toss everything together vigorously, ensuring the heat from the pasta and bacon cooks the eggs, creating a creamy sauce. If the sauce seems too thick, add a bit of the reserved pasta cooking water to reach your desired consistency.

Serve the spaghetti carbonara immediately with extra Parmigiano-Reggiano grated over the top, and a sprinkle of fresh parsley if desired.