Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the shredded chicken, cream of chicken soup, sour cream, and 1 cup of cheddar cheese. If adding mixed vegetables, toss them in now with salt and pepper to taste.
Pour the chicken mixture into a greased 9x13-inch baking dish, spreading it evenly.
In a separate bowl, combine the crushed crackers and melted butter until well mixed. Sprinkle this crunchy topping evenly over the chicken mixture.
Top the casserole with the remaining ½ cup of shredded cheddar cheese.
Place the casserole in the preheated oven and bake for 30-35 minutes or until heated through and bubbly. The topping should be golden brown.
Let the casserole cool for a few minutes before serving.
