Cook spaghetti in a large pot of salted boiling water until al dente. Reserve 1 cup of pasta water, then drain.
In a skillet, heat olive oil over medium heat. Add pancetta and cook until crisp and golden, about 5 minutes. Remove from heat.
In a bowl, whisk eggs with Pecorino Romano and a generous amount of black pepper until smooth.
Add minced garlic to the pancetta in the skillet, allowing the residual heat to soften it without browning.
Return the drained pasta to the pot. Off the heat, pour the egg mixture over the pasta, stirring vigorously to coat evenly.
Gradually add reserved pasta water, a few tablespoons at a time, until the sauce reaches a creamy consistency.
Toss in the crispy pancetta and garlic, ensuring even distribution throughout the pasta.
Serve immediately, garnished with extra cheese and black pepper if desired.