Preheat the oven to 400 degrees Fahrenheit and spray a 9x13-inch baking dish with non-stick cooking spray.
Add the 2 diced chicken breasts,10 ounces penne pasta, 2 cups heavy cream, 2 ½ cups chicken broth, 2 cups chopped spinach, 2 (8-ounce) jars drained and chopped sundried tomatoes, 2 teaspoons Italian seasoning, 1 ½ teaspoon garlic powder, 1 teaspoon onion powder, 1 teaspoon salt, and ½ teaspoon pepper to the baking dish.
Stir everything together to combine, cover with foil, and bake for 30 minutes. Remove from the oven and stir to ensure all the pasta is coated in liquid. Cook for 20 more minutes, then remove the foil and stir the casserole again.
Top the dish with 1 cup shredded parmesan cheese and 1 cup grated mozzarella cheese and bake for an additional 5 minutes, until the cheese is melted and bubbly.
Remove from the oven and stir in the cheese, and let it rest a few minutes before serving.