Bring a large pot of salted water to a rolling boil. Add penne pasta and cook according to package instructions until al dente, about 9-12 minutes. Drain, reserving 1 cup of pasta water.

In a large skillet, heat olive oil over medium heat. Add chopped onion and minced garlic, sautéing until fragrant and onion is translucent, about 3 minutes.

Lower the heat and add softened cream cheese and ranch seasoning mix. Stir until cream cheese melts. Gradually pour in chicken broth and heavy cream, stirring until thickened, about 5 minutes.

Incorporate shredded chicken and sharp cheddar cheese into the sauce, stirring until cheese melts and blends with the sauce.

Fold cooked penne into the creamy sauce. If thick, add reserved pasta water. Stir in half of the crumbled bacon.

Remove from heat. Divide among plates and garnish with remaining bacon and parsley. Serve immediately.