Preheat oven to 350°F (175°C).
In a large bowl, mix sour cream, cream of chicken soup, mayonnaise, garlic powder, onion powder, salt, and pepper.
Stir in the shredded chicken, cooked rice, and broccoli if using.
Pour mixture into a greased 9x13-inch baking dish.
Sprinkle shredded cheddar cheese evenly on top.
Top with crushed crackers for a crunchy finish.
Bake for 30–35 minutes, until bubbly and golden.
Serve warm and enjoy!