Preheat the air fryer: Set to 325°F (160°C) for a few minutes. A lower temp prevents burning and ensures even roasting.
Mix the wet ingredients: In a large bowl, whisk the oil, maple syrup (or honey), vanilla, and orange zest if using.
Combine spices: In a small bowl, stir together salt, cinnamon, smoked paprika, cayenne, cumin, and brown sugar if using.
Coat the nuts: Add the nuts to the wet mixture and toss to coat. Sprinkle the spice blend over the nuts and toss again until evenly covered.
Prepare the basket: Lightly spray the air fryer basket.
Spread the nuts in a single layer. If your basket is small, cook in two batches.
Air fry: Cook for 6–9 minutes at 325°F (160°C), shaking the basket every 2–3 minutes. Watch closely for the last few minutes—nuts can go from perfect to burnt quickly.
Cool and set: Transfer the nuts to a parchment-lined tray.
They will crisp up as they cool. Let them sit for 10–15 minutes.
Taste and finish: While still slightly warm, sprinkle a pinch more salt if needed. Break apart any clusters after cooling.