Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.

In a large mixing bowl, combine the cooked shredded chicken, cream of chicken soup, sour cream, optional finely chopped onion, garlic powder, and black pepper until a smooth mixture forms.

Spread the chicken mixture evenly in the prepared baking dish.

In a separate bowl, mix crushed Ritz crackers with melted butter and optional grated Parmesan cheese until combined.

Sprinkle the cracker mixture evenly over the chicken layer.

Bake uncovered for about 30-35 minutes until golden brown and bubbly.

Let it sit for about 5 minutes, then garnish with freshly chopped parsley before serving.