0 Preheat the air fryer to 390°F (199°C) if the manufacturer recommends preheating.
1 In a large bowl, whisk the gochujang, 40 ml hot water and Splenda until smooth. Add the remaining 10 ml water only if needed to make a thick, pourable marinade.
2 Pat the chicken dry, add it to the bowl and turn until every piece is evenly coated.
3 Lightly coat the air-fryer basket with cooking spray. Arrange the thighs in a single layer without overlapping; cook in batches as needed. Lightly spray the tops and season evenly with black pepper.
4 Air fry each batch for 10–12 minutes, turning halfway through, until browned and the thickest part of every thigh reaches at least 165°F (74°C). Air fryers and thigh thickness vary, so use temperature rather than crispness alone to determine doneness.
5 Rest for 3 minutes, then slice or serve whole with rice, a wrap or salad if desired.
