Preheat an air fryer to 350 degrees F (175 degrees C) according to manufacturer's instructions.

Place peach halves flesh-sides down in air fryer basket; cook for 6 minutes.

Meanwhile, place butter in a microwave-safe bowl; microwave in 15 to 30 second intervals until melted. Stir in brown sugar and cinnamon until sugar has dissolved; microwave in 10 to 15 second intervals, if needed.

Flip peaches flesh-sides up using tongs; brush butter mixture over tops, filling pit cavities with any excess. Cook 6 minutes more.

Cool peaches for 5 minutes; top each half with 1 scoop ice cream.