1. Bring a large pot of salted water to a boil and cook your pasta according to the package instructions until al dente. Reserve 1/4 cup of the pasta cooking water, then drain and set aside.
2. In the meantime, heat olive oil in a large skillet over medium heat. Add the chopped bacon and cook until crispy, about 5-7 minutes. Transfer the bacon to a paper towel-lined plate, leaving the bacon fat in the pan.
3. Add the sliced onions to the skillet and cook over low heat, stirring occasionally, until they are golden brown and caramelized, about 20-25 minutes. This step takes patience but is key to the depth of flavor.
4. Add the minced garlic to the onions and cook for an additional 1-2 minutes until fragrant.
5. Return the cooked bacon to the skillet and toss with the onions and garlic.
6. Add the drained pasta to the skillet, along with the Parmesan cheese and reserved pasta water. Toss everything together over medium heat until well combined and heated through.
7. Season with salt and pepper to taste, and sprinkle with fresh parsley if using.
8. Serve hot and enjoy a moment of pure culinary bliss.

I’ve found that using a wooden spoon to stir the onions allows for even caramelization and prevents them from burning—a trick I picked up from my dad during those early kitchen adventures.