Cook spaghetti in large pot of salted boiling water for 8 to 10 minutes, or until al dente. Drain and reserve 1/2 cup pasta water.
Meanwhile, cook pancetta in large skillet set over medium high heat for 7 to 8 minutes or until crisp. Add garlic and cook for 1 minute; add pasta to skillet.
Meanwhile, whisk together eggs, 3/4 cup Parmesan cheese and 1/4 tsp pepper; stir into pasta along with peas. Toss for about 30 seconds or until pasta is coated and eggs are slightly set. Stir in reserved pasta water.
Sprinkle with remaining Parmesan cheese and parsley; season with pepper to taste. Serve immediately.