In a large pot, bring salted water to a boil. Add the penne pasta and cook according to package instructions until al dente. Drain and set aside.

In a skillet over medium heat, combine the cream cheese, chicken broth, ranch dressing, garlic powder, onion powder, salt, and black pepper. Stir until the cream cheese is melted and the mixture is smooth.

Add the shredded chicken to the sauce and stir to combine. Cook for an additional 5 minutes until heated through.

Add the cooked penne pasta to the skillet and toss until the pasta is well coated with the sauce.

Serve hot, garnished with chopped green onions and additional cheddar cheese if desired.