Steam or microwave the broccoli florets until tender, about 4-5 minutes. Drain and set aside.
In a large bowl, combine the cream of chicken soup, mayonnaise, egg, 1 cup of the shredded cheddar cheese, onion powder, garlic powder, salt, and pepper. Stir until smooth.
Fold the cooked broccoli into the mixture, making sure the broccoli is well coated.
Transfer the broccoli mixture to a greased 9x13-inch baking dish, spreading it out evenly.
Sprinkle the remaining cup of cheddar cheese over the top.
In a small bowl, combine the crushed Ritz crackers and melted butter. Sprinkle the cracker mixture evenly over the cheese.
Bake in the preheated oven for 25-30 minutes, or until the top is golden and bubbly.
Let the casserole cool for a few minutes before serving.