Bring a large pot of salted water to a boil. Cook the spaghetti according to the package instructions until al dente.
While the spaghetti is cooking, heat olive oil in a large skillet over medium heat. Add the pancetta and cook until crispy, about 5-7 minutes. Remove pancetta from the skillet and set aside.
In the same skillet, add minced garlic and sauté until fragrant, about 1 minute.
In a small bowl, whisk together eggs and Parmesan cheese until well combined.
Drain the cooked spaghetti, reserving 1/2 cup of the pasta water. Add the spaghetti to the skillet with garlic and toss to combine.
Remove the skillet from heat and quickly add the egg mixture, stirring constantly to create a creamy sauce. If the sauce is too thick, add some reserved pasta water to reach the desired consistency.
Stir in the crispy pancetta, season with salt and pepper, and garnish with chopped parsley if desired.
Serve immediately with extra Parmesan cheese on top.