Bring the water to a boil in a 6-quart pot, stir in the salt and penne, and cook according to the package directions until al dente. Reserve 1/4 cup of the cooking water, then drain the pasta.

Season the chicken with the black pepper. Heat the olive oil in a 12-inch skillet over medium-high heat, add the chicken, and cook for 6–8 minutes, stirring occasionally, until browned and it reaches 165°F; transfer to a plate.

Add the bacon to the skillet and cook over medium heat for 5–7 minutes, stirring occasionally, until crisp. Transfer it to a paper towel-lined plate, then leave about 1 tablespoon of bacon drippings in the skillet and discard the rest.

Add the garlic to the skillet and cook over medium heat for 30 seconds. Add the broth, heavy cream, cream cheese, and ranch seasoning; whisk over medium-low heat for 3–5 minutes, until the cream cheese has melted and the sauce is smooth and gently simmering.

Stir in the Parmesan and reserved pasta water, then add the drained pasta, chicken, and bacon and toss until evenly coated. Serve hot.