Bring a large pot of heavily salted water to a rolling boil.

Cook the penne pasta according to the package directions until exactly al dente, about 10 minutes.

Before draining, carefully reserve at least 1 cup of the highly starchy pasta cooking water. Drain the pasta and set aside.

While the pasta cooks, heat the olive oil in a large, deep skillet over medium-high heat.

Add the 1-inch bacon pieces to the skillet and cook until the fat renders and the edges begin to crisp, about 5 minutes.

Add the diced white onion to the rendered bacon fat.

Cook over medium-high heat until the onions are completely soft, translucent, and just beginning to caramelize and brown.

Season the bacon and onion mixture with the kosher salt and coarse black pepper.

In a small ceramic mixing bowl, vigorously whisk together the 3 large eggs and the grated Parmesan cheese until fully combined into a thick paste.

Transfer the hot, drained penne pasta directly into the skillet with the bacon and onions.

Remove the skillet from the direct heat to prevent the eggs from scrambling.

Pour the egg and cheese paste directly over the hot pasta and toss rapidly.

Slowly ladle 1 to 2 splashes of the reserved, hot pasta water into the skillet while continuing to toss. The hot water will gently cook the eggs and emulsify the fat into a smooth, luxurious cream sauce.

Toss the fresh chopped oregano into the pan, folding it into the glossy sauce.

Serve the pasta immediately, directly from the warm skillet, heavily garnished with additional grated Parmesan cheese.