Cook the pasta according to the package directions.
Meanwhile, fry the bacon in a large skillet over medium heat. Transfer to a paper towel and reserve the drippings.
In a large bowl, whisk the egg yolks. Still whisking constantly, add 2 tablespoons of the drippings. Working quickly, add the drained pasta and Parmesan to the yolk mixture and toss to combine. Add the salt, pepper, parsley, and bacon. Serve immediately. (The heat of the pasta cooks the eggs, but not thoroughly. It may be advisable for young children, the elderly, and anyone with a compromised immune system to avoid eating this dish.)
Tip: Use a pair of clean scissors or kitchen shears, not a knife, to dice the bacon. It's much quicker and makes less of a mess.