Start by bringing a large pot of salted water to a rolling boil over high heat. Add spaghetti and cook according to package instructions until al dente, usually about 8-10 minutes. Once done, drain pasta in a colander, reserving ½ cup of pasta water for later use.

In a large skillet, heat over medium heat, adding the chopped bacon. Cook the bacon for about 5-7 minutes until it's crispy and golden brown. Remove bacon with a slotted spoon to paper towels to drain; leave the bacon fat in the skillet.

In the same skillet with the leftover bacon fat, add unsalted butter. Heat over medium until butter melts, then add minced garlic. Sauté for about 1 minute or until fragrant, stirring frequently to avoid burning the garlic.

Pour heavy cream into the skillet with garlic, stirring gently to combine. Bring the mixture to a gentle simmer over low heat, allowing it to thicken slightly. Slowly whisk in grated Parmesan cheese until it is fully melted and the sauce is creamy and smooth. Season with salt, pepper, and optional red pepper flakes to taste.

Once your sauce is ready, add the cooked spaghetti along with crispy bacon back into the skillet. Toss everything together, ensuring the spaghetti is fully coated in the rich cream sauce. If the sauce appears too thick, gradually add reserved pasta water until you reach your desired consistency.

Remove the skillet from heat and transfer Cream Spaghetti with Bacon to serving plates. For a fresh finish, sprinkle with chopped fresh parsley. Serve immediately.