Preheat your oven to 350°F (175°C). Gather all your ingredients and equipment.

In a large pot, bring salted water to a boil. Cook the penne pasta for 8-10 minutes until al dente, then drain and set aside.

If using cooked chicken, shred it into bite-sized pieces.

In a medium saucepan, combine heavy cream, butter, garlic, and grated Parmesan cheese. Heat until melted and thickened (about 5-7 minutes).

In a large mixing bowl, combine cooked pasta, shredded chicken, Alfredo sauce, garlic powder, Italian seasoning, salt, and pepper. Mix thoroughly.

Grease a 9×13-inch baking dish. Transfer the pasta and chicken mixture into the dish and top with mozzarella and Parmesan cheese.

Bake in the preheated oven for 25-30 minutes until cheese is melted and golden.

Let the dish cool for 5-10 minutes before serving. Garnish with chopped parsley.