Preheat your oven to 350°F (175°C).
In a large pot, bring water to a rolling boil and add the broccoli florets. Blanch them for about 2-3 minutes until they turn a vibrant green, then drain and set aside to cool.
In a mixing bowl, combine the cooked rice, sharp cheddar cheese, cream of mushroom soup, milk, garlic powder, onion powder, black pepper, and sea salt. Stir until everything is well blended.
Gently fold in the blanched broccoli, ensuring it is thoroughly coated with the creamy mixture.
Pour the entire mixture into a greased 9x13-inch baking dish, spreading it out evenly.
In a separate bowl, combine the crushed crackers with the melted butter, mixing until the crackers are well coated.
Sprinkle this buttery cracker topping generously over the casserole.
Place the dish in the oven and bake for 25-30 minutes, or until the casserole is hot and bubbly, with a golden crust on top.
Once done, take it out of the oven and allow it to cool for a few minutes before serving.