Bring a large pot of salted water to boil. Cook spaghetti according to package directions until al dente (usually 8-9 minutes). Reserve 1 cup of pasta water before draining.

While pasta cooks, cut pancetta into small cubes. Cook in a large skillet over medium heat until crispy and fat has rendered, about 5-6 minutes.

In a bowl, whisk together egg yolks, grated Pecorino Romano cheese, and plenty of black pepper. Add a splash of pasta water to create a creamy sauce.

Drain pasta and immediately add to the pancetta skillet (remove from heat first). Toss to coat.

Pour egg mixture over pasta and toss vigorously off heat. The residual heat will cook the eggs into a creamy sauce. Add pasta water as needed for consistency.