Start by preheating your oven to 375°F (190°C) to ensure it's hot and ready for your casserole.
In a large mixing bowl, combine the softened cream cheese and sour cream. Sprinkle in the garlic powder, onion powder, dried Italian herbs, salt, and pepper. Mix thoroughly using a spatula or whisk until the mixture is smooth and well integrated.
Gently fold in the shredded chicken, roughly chopped spinach, cooked pasta, half of the mozzarella cheese, and half of the Parmesan cheese. Stir thoughtfully until all the ingredients are evenly coated with the creamy mixture.
Carefully transfer the mixture to a greased 9x13 inch baking dish, spreading it out evenly to ensure an even bake.
Evenly sprinkle the remaining mozzarella and Parmesan cheese over the top of the casserole. If you desire an extra crunch, you can add the breadcrumbs on top. Drizzle the olive oil over the breadcrumbs for enhanced flavor and crispiness.
Place the baking dish in the preheated oven and bake for 25-30 minutes. You’ll know it’s done when the casserole is bubbly and the cheese is beautifully golden brown.
Once baked, remove the casserole from the oven and let it cool for about 5 minutes. This will help the flavors settle and make it easier to serve.
Notes
Serve warm, garnished with fresh parsley or basil. Pairs well with a light salad or crusty artisan bread.