Prep the sweet potatoes: Peel if you prefer a cleaner look, or leave the skin on for texture and nutrients. Cut into 1/4- to 1/2‑inch thick sticks. Keep the pieces as even as possible so they cook at the same rate.

Soak briefly (optional but helpful): Place the cut fries in a bowl of cold water for 15–20 minutes. This draws out excess starch and helps with crispiness.

Dry thoroughly: Drain and pat the fries very dry with clean towels. Any moisture left on the surface turns to steam and softens the edges.

Toss with starch: In a large bowl, sprinkle the cornstarch over the fries and toss to lightly coat. You want a thin, even dusting with no clumps.

Add oil and spices: Drizzle on the oil and sprinkle in salt, pepper, smoked paprika, garlic powder, and cayenne if using. Toss until every piece is well coated.

Preheat the air fryer: Set it to 380°F (193°C) for 3–5 minutes. A hot basket helps form a crust quickly.

Load the basket: Arrange the fries in a single layer with a little space between them. Do not overcrowd. Work in batches if needed.

Air fry the first side: Cook at 380°F for 8 minutes. Resist the urge to open the basket too often.

Shake and continue: Shake the basket or flip the fries. Air fry for another 6–8 minutes until the edges are crisp and browned. Thicker fries may need an extra 2–3 minutes.

Season and serve: Taste and add a pinch more salt if needed. Garnish with herbs and serve hot with a squeeze of lemon or your favorite dip.