In a large pot of boiling salted water, cook spaghetti pasta until al dente (about 6-10 minutes). Drain. (Can reserve a cup of pasta water just in case you want a thinner sauce.) Toss with 1 tablespoon of olive oil, and set aside.
In a large skillet over medium heat, add chopped bacon and cook until crisp; remove and drain onto paper towels.
To the same skillet over medium heat (That has not been drained or cleaned! You should have about 2 tablespoons of bacon fat remaining in the fan - if you don't add some olive oil.), add chopped onion.
Once onion is translucent (about 3-5 minutes) add the minced garlic, and cook for one more minute.
Add the spaghetti noodles back into the pan and toss to coat and heat through. Reduce the heat to low.
In a medium bowl, mix together eggs and parmesan cheese. Add this to the noodles and cook, tossing constantly with tongs until eggs and parmesan develop into a light sauce over the noodles.
Add in bacon, salt and pepper to taste, and top with remaining parmesan cheese. (And chopped parsley for garnish if you so desire.)