Cook the penne pasta according to package instructions until al dente.
In a large mixing bowl, combine shredded chicken, ranch seasoning, and cream cheese.
Add the cooked penne pasta to the chicken mixture and stir to combine.
Stir in the chicken broth, cheddar cheese, and sour cream, mixing well.
Season with salt and pepper to taste, adjusting as necessary.
Transfer the mixture to a greased baking dish and top with additional cheddar cheese.
Bake at 350°F (175°C) for about 20-25 minutes or until the cheese is bubbly and golden.
Garnish with chopped green onions before serving for a fresh touch.