Place beef bacon or smoked turkey strips in a cold skillet or Dutch oven. Cook over medium heat until crisp. Transfer to a paper towel–lined plate and crumble; leave about 1 teaspoon of the rendered fat in the pot.

Add olive oil if needed and raise heat to medium-high. Season diced chicken with half the ranch mix, a pinch of salt, and black pepper. Sear 5–7 minutes, stirring once or twice, until golden and cooked through. Transfer to a plate with any juices.

Lower heat to medium. Pour in chicken broth, scraping up browned bits. Stir in remaining ranch seasoning, garlic powder, onion powder, and red pepper flakes if using. Bring to a boil.

Add uncooked penne. Reduce to a lively simmer, cover, and cook 10–12 minutes, stirring every few minutes, until the pasta is al dente and liquid is mostly absorbed.

Reduce heat to low. Stir in the softened cream cheese until fully melted and smooth. Add milk a splash at a time to reach a creamy consistency.

Return the cooked chicken and any accumulated juices to the pot. Stir to coat.

Sprinkle in cheddar and mozzarella gradually, stirring between additions until the sauce is glossy and the cheeses are melted.

Stir in most of the crumbled beef bacon, reserving a little for topping. Taste and adjust salt and pepper as needed.

Serve hot, garnished with remaining beef bacon and chopped parsley or green onions.