Preheat the oven to 350℉. Spray a 9x9-inch glass pyrex dish with nonstick spray.
In a large bowl, combine the chicken, soup, cheddar cheese, sour cream, green onion, chicken broth, Dijon, garlic powder, onion powder, pepper and salt. Scrape the mixture into the prepared dish and smooth the top.
In a separate bowl, crush the Ritz crackers and drizzle the butter on top. Sprinkle the buttered crackers on top of the chicken mixture.
Bake for 30 minutes, or until the top is golden brown and the casserole is hot and bubbly.