Preheat oven to 450. Spray a baking sheet with olive oil. Set aside. Mix the garlic powder, salt, pepper, melted butter, and hot sauce in a small bowl. Add the cauliflower into a large gallon-sized bag, pour the buffalo sauce into the bag. Shake until the cauliflower florets are fully coated. Spread on a baking sheet. Bake for 20 minutes. Serve with ranch or blue cheese dressing.