Bring a large pot of water to a boil, add salt, and cook the spaghetti until al dente, about 8-10 minutes. Drain and set aside, reserving some pasta water.
While pasta cooks, heat a skillet over medium heat. Add the diced pancetta and cook until crispy and golden brown, about 5-7 minutes, stirring occasionally. Transfer to a plate lined with paper towels and set aside.
In a mixing bowl, whisk together the eggs, grated Parmesan, and black pepper until fully combined and slightly frothy.
Return the drained pasta to the hot skillet (off heat), add the cooked pancetta, and toss well to combine. Pour the egg mixture over the pasta while tossing continuously. The residual heat will cook the eggs gently, creating a creamy sauce. If the mixture seems too thick, add a splash of reserved pasta water to loosen it up.
Serve immediately, garnished with additional black pepper and extra Parmesan if desired. The sauce should be glossy and cling to the noodles, with bits of pancetta visible throughout.
