Cook the rotini pasta according to package instructions until al dente. Drain and set aside.
In a large mixing bowl, combine the shredded chicken, ranch dressing, mozzarella cheese, cheddar cheese, cream cheese, garlic powder, onion powder, and seasoning. Mix well until fully incorporated.
Add the cooked rotini pasta and frozen peas (if using) into the cheese and chicken mixture. Fold gently until the pasta is fully coated and all ingredients are combined.
Transfer the mixture into a greased 9x13 inch baking dish and spread it evenly.
Top with an extra sprinkle of mozzarella and cheddar cheese if desired.
Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden.
Remove from the oven and allow to cool for a few minutes. Garnish with freshly chopped parsley before serving.