Preheat oven to 450 degrees. Toss the cauliflower florets in olive oil. In a large bowl, mix the ranch dressing packet with the water. Add the cauliflower to the ranch mixture, tossing to coat the cauliflower completely. Bake for 20-25 minutes. Meanwhile, melt the butter in the microwave and whisk in the hot sauce. Remove the cauliflower from the oven and pour the butter and buffalo sauce mixture over the cauliflower, tossing to cover the cauliflower completely. Bake for another 5-7 minutes until the cauliflower begins to brown and become crispy. Serve with a side of ranch or blue cheese dressing and celery. Enjoy!