- Stir together melted butter and hoisin sauce in a small bowl. Pour half of the hoisin butter mixture over sweet potatoes and stir well to coat.
- Grease basket of air fryer with cooking oil spray and add potatoes in an even layer. Air fry at 380ºF for 8 minutes.
- Shake air fryer basket to rotate potatoes and continue to air fry for 7-8 minutes longer, until tender.
- Reheat remaining hoisin butter in microwave for about 10 seconds if needed. Transfer potatoes to a serving plate and drizzle with butter mixture. Top with chopped peanuts and cilantro.