Wash the cauliflower and cut into bite-sized florets. Making them fairly uniform helps ensure even cooking and avoids some pieces being overcooked while others are underdone. Dry them lightly so oil and seasonings clings instead of slipping off.
In a bowl, toss the florets with olive oil, garlic powder, paprika, and a pinch of salt until everything is coated. Preheat your air fryer to 400°F (about 200°C), then spread the cauliflower in a single layer in the basket. Cook for about 15 minutes, giving the basket a shake or flipping halfway through to ensure all sides crisp up.
While cauliflower is cooking, melt the butter and combine it with buffalo sauce so the sauce is warm and well-blended. Once the cauliflower is done, move it to a bowl and toss it with the sauce until every floret is well coated. Serve immediately so the texture is still crisp and the sauce still vibrant.