Preheat your oven to 450°F (230°C). A hot oven is key to achieving crispy cauliflower bites.
Wash and dry the head of cauliflower. Cut it into bite-sized florets, ensuring they are relatively uniform in size for even cooking.
In a large mixing bowl, combine the cauliflower florets, 1 teaspoon of garlic powder, onion powder, Kosher salt, freshly ground pepper, and cayenne pepper. Drizzle with the olive oil and toss until all the florets are well-coated.
Spread the seasoned cauliflower evenly on a baking sheet. Roast in the preheated oven for about 20 minutes, flipping halfway through, until golden brown and crispy.
While the cauliflower is roasting, melt the butter in a small saucepan over low heat. Once melted, stir in the hot sauce and the remaining teaspoon of garlic powder. Mix until well combined and heated through.
Once the cauliflower is done roasting, pour the buffalo sauce over the hot cauliflower on the baking sheet. Toss gently to coat all the florets evenly.
Return the coated cauliflower to the oven and bake for an additional 10 minutes. This will help the sauce caramelize slightly and intensify the flavor.
Remove from the oven and let cool for a few minutes. Serve with celery stalks and blue cheese dressing on the side.