Put a large pot of water on to boil. Meanwhile, crack eggs into a large bowl and beat lightly. Finely shred or grate cheese, add 1/2 cup to eggs, and set the rest aside. Finely chop parsley and add to eggs. Add pepper and whisk to combine well. Set aside.
Cut pancetta or bacon into 1/4-in.-thick slices, peel and chop garlic, and set both aside. Heat olive oil in a small frying pan over medium-high heat. Add pancetta and cook, stirring occasionally, until it starts to brown. Add garlic and cook, stirring, until fragrant, about 1 minute. Add wine and cook until liquid is reduced by about half. Remove from heat and set aside.
When water boils, add salt and spaghetti. Boil pasta until it is tender to the bite. Drain well and immediately pour pasta into bowl with egg mixture. Toss to thoroughly coat pasta with egg mixture (the heat from the pasta will partly cook the egg and melt the cheese). Pour pancetta mixture on top of pasta and toss to combine thoroughly. Sprinkle with remaining cheese and pepper to taste. Serve immediately.
Peas, please: Add 3/4 cup frozen peas to the egg mixture.
Add radicchio: Finely shred 1 small head radicchio and cook with the pancetta.
Pick basil: Substitute 1/4 cup chopped fresh basil leaves for the parsley.
Spice it up: Add 1/2 tsp. red chile flakes with the garlic.
Change the cheese: Substitute other hard, aged cheese (such as asiago, pecorino, or aged gouda) for the parmesan.
Go for whole grain: Try using whole-wheat spaghetti (the assertive, rich flavors of this dish will hold up to a heartier pasta beautifully).
Note: Nutritional analysis is per serving.