Remove outer leaves and core from one medium-large head of cauliflower (about 1½–1¾ lb.). Cut into even 2-inch florets — uniform size is key for even cooking. Toss thoroughly in a large bowl with oil, salt, pepper, and any dry spices. Use your hands to coat every surface. Even oil coverage drives browning and crispness, so don't rush it.

Preheat air fryer to 390–400°F for 5 minutes. Arrange seasoned florets in a single layer — no overcrowding or they'll steam instead of brown. Air fry at 390–400°F for 12–18 minutes, shaking the basket at least once halfway through. Small florets are done around 12 minutes; larger, denser ones may need up to 18. Cook in batches if needed, loosely covering the first batch to keep warm.

Cauliflower is done when florets are deeply browned at the edges and tender when pierced with a fork — crisp-tender, no raw chalky center. If pale and soft, cook another 2–3 minutes and recheck. Season with salt and pepper right away. Add fresh parsley or toss in sauce (like honey sriracha) while still hot so it sticks. Serve immediately — the crisp exterior softens quickly. Don't cover and steam before serving.