Marinate the Chicken. In a large bowl, whisk together balsamic vinegar, honey, minced garlic, olive oil, rosemary, salt, and pepper. Add chicken breasts, ensuring they are fully coated. Marinate for at least 15 minutes, or for a more robust flavor, up to 4 hours in the refrigerator.
Prepare for Cooking. Preheat your air fryer to 375°F. Remove chicken from the marinade and reserve the liquid.
Air Fry to Perfection. Place chicken in a single layer in the air fryer basket. Cook for 10 minutes, flip, then brush with reserved marinade and cook for an additional 10 minutes or until the internal temperature reaches 165°F.
Reduce the Marinade. While the chicken cooks, pour the reserved marinade into a small saucepan. Bring to a boil, then reduce to a simmer and let it thicken slightly to form a glaze.
Serve and Enjoy. Drizzle the reduced balsamic glaze over the cooked chicken. Garnish with fresh rosemary sprigs or a sprinkle of parsley for a fresh, herby finish.