With 1 bacon slice, wrap 3-4 asparagus stalks.
Repeat with remaining bacon slices and asparagus.
Grease the Air Fryer Basket with cooking spray and then slide inside.
Adjust the temperature of Air Fryer to 390 °F to preheat for 5 minutes.
In a small bowl, mix together the butter, brown sugar, salt and black pepper.
Coat each asparagus bundle with butter mixture.
After preheating, arrange the asparagus bundles into the greased Air Fryer Basket in a single layer.
Slide the basket into Air Fryer and set the time for 10 minutes.
After cooking time is finished, remove the asparagus bundles from Air Fryer and serve.