Preheat & Prepare Dish: Preheat your oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish with non-stick cooking spray or softened butter.

Whisk the Cream Base: In a large mixing bowl, beat the softened cream cheese with a hand mixer or wooden spoon until smooth and lump-free. Add the sour cream, cream of chicken soup, garlic powder, onion powder, kosher salt, black pepper, and half of the fresh parsley. Whisk until completely creamy and silky.

Fold in Chicken & Cheeses: Add the shredded chicken, 1 cup shredded mozzarella, and 1/2 cup shredded cheddar cheese into the bowl. Fold gently with a spatula until the chicken is thoroughly and evenly coated in the luxurious sauce.

Spread into Baking Dish: Transfer the chicken mixture into the prepared 9x13-inch baking dish. Use the back of a spoon or offset spatula to spread it into an even layer.

Prepare Ritz Topping: In a medium bowl, combine the coarsely crushed Ritz crackers, melted butter, and 1/4 tsp garlic powder. Toss with a fork until the crumbs are evenly coated in golden melted butter.

Top the Casserole: Scatter the buttery Ritz cracker crumbs evenly across the entire surface of the casserole, creating a generous crunchy blanket.

Bake to Golden Perfection: Bake uncovered at 350°F (175°C) for 30 to 35 minutes, until the casserole is bubbling hot around the edges and the cracker topping is deeply golden brown and crisp.

Garnish & Rest: Remove from the oven and let rest for 5 to 10 minutes so the creamy filling can set slightly. Garnish with remaining chopped fresh parsley and serve warm!