Gather all ingredients.
Preheat the oven to 350 degrees F (175 degrees C). Stir together shredded chicken, cream of chicken soup, scallions, sour cream, chicken broth, mustard, garlic powder, onion powder, black pepper, and salt in a 9x13-inch baking dish. Spread into an even layer.
Stir crackers and butter together in a bowl until coated, and sprinkle evenly over chicken mixture.
Bake in the preheated oven until bubbly and crackers are golden brown, about 30 minutes. Garnish with sliced scallions.
