Place bread crumbs in a medium bowl. Add half the salt and half the black pepper to the bread crumbs and stir to combine. Pour mixture onto a shallow plate.
Place flour in another medium bowl. Add remaining salt and remaining black pepper to the flour and stir to combine. Pour mixture onto a shallow plate.
In another medium bowl, whisk both eggs.
Cut avocados in half and remove the pit. Use a spoon to carefully loosen the avocado flesh from the shell. Lift out in one piece. Place avocado flat side down on cutting board and cut into 1/2-inch slices.
Dredge a slice of avocado in the flour. Dip floured avocado in whisked egg, then press into the bread crumbs. Place on a wire rack. Repeat for all slices.
Spray breaded slices with olive oil spray.
Preheat air fryer to 390 F.
Place slices into the air fryer basket, being sure to leave space between each slice.
Air fry 7 minutes. Turn each slice over and air fry for another 5 minutes.
Notes
You actually want to use firm avocados to make these fries. You don't want underripe avocados, nor do you want them to be soft - a good in-between of the two is what we are going for. Look for firm avocados with a slight give when gently squeezed. You need to be able to rely on their structural integrity for dipping into the breading.
Air fryer avocado fries are best served right away, but you can store any leftovers in an air-tight container kept in the refrigerator for up to 1 day. Reheat using the reheat function on the air fryer.