How to Make It
In a large bowl of cold water, soak sweet potato slices for 20 minutes. Drain sweet potatoes; pat dry with paper towels.
Wipe bowl dry; then add oil, salt, pepper, and rosemary (if using). Add sweet potatoes; toss gently to coat.
Lightly coat air fryer basket with cooking spray. Place half of the sweet potatoes in the basket, and cook in two batches at 350°F until cooked through and crispy, about 15 minutes.
Using a pair of tongs, carefully remove sweet potatoes from air fryer to plate. Let cool; serve immediately or store in an airtight plastic container.
We used a Philips Viva Collection HD9621 Air Fryer, which does not need preheating.
Air frying these sweet potato chips takes a little practice—but you can nail them by keeping a close eye on them while they cook. Check the chips about halfway through, using your tongs to separate any that have stuck to each other. Check them again towards the end of their cook cycle, making sure to remove any chips that are lightly-browned and crisped. Don’t worry if several chips feel a touch soft—they tend to dry out and crisp up as they cool.