Wash and dry the baby potatoes thoroughly. Halve any larger ones to ensure uniform size for even cooking and crispiness.
In a bowl, combine olive oil, finely minced garlic or garlic powder, chopped fresh rosemary, salt, and pepper. Toss the potatoes until all pieces are evenly coated to maximize flavor.
Preheat the air fryer to 400°F (200°C) and allow it to preheat for about 3 minutes to ensure immediate crisping.
Place the seasoned potatoes in the air fryer basket in a single layer without overcrowding. Cook for 15-20 minutes, shaking the basket or stirring the potatoes halfway through for uniform golden browning.
Remove the potatoes once they are crisp and tender. Optionally, sprinkle with freshly grated Parmesan or a squeeze of lemon juice to enhance brightness. Serve immediately to enjoy optimal texture.