Preheat oven to 425 F/220 C.In a medium sized bowl, add brown rice flour, onion powder, garlic powder, and salt. Mix. Next, add in water and stir well. This batter will be very dense.Rinse, dry, and cut cauliflower into bite size bits. Place each piece in the batter, coating evenly. Then place each piece on a baking sheet.Place the cauliflower in the oven for 20 minutes. During this time, prepare your buffalo sauce.In a small bowl, heat up the butter so it's in liquid form.Then, add the hot sauce and mix well.When the cauliflower is ready, remove from the oven and dip each piece in the buffalo sauce, coating completely.Place back in the oven for another 10 minutes. Brush any remaining hot sauce onto the cauliflower once done.