Preheat the air fryer to 425°F.
Place the cauliflower florets in a large bowl. Add the avocado oil and ¼ teaspoon sea salt, then toss to coat.
Arrange the cauliflower in the air fryer basket without overcrowding it. Cook in batches if needed. Air fry for about 12 minutes.
Meanwhile, melt the vegan butter in a small saucepan over low heat. Stir in the tapioca starch, hot sauce, apple cider vinegar, coconut aminos or gluten-free tamari, granulated garlic, and ½ teaspoon sea salt until smooth and well combined.
Transfer the cauliflower to a bowl and gently toss with half of the buffalo sauce. Reserve the remaining sauce.
Return the cauliflower to the air fryer and cook at 425°F for another 2 minutes.
Transfer to a serving plate, drizzle with the remaining buffalo sauce, and serve warm with your favorite dairy-free dipping sauce.