Begin by washing the asparagus thoroughly. Trim the hard ends by about 1-2 inches.
In a mixing bowl, combine the olive oil, garlic powder, salt, and black pepper.
Add the trimmed asparagus to the mixing bowl and toss until all the asparagus are well coated with the oil and seasonings.
Preheat the air fryer to 400°F (200°C) for about 3 minutes.
Place the seasoned asparagus in a single layer in the air fryer basket. Avoid overcrowding for even cooking.
Cook in the air fryer for 7 minutes, shaking the basket halfway through for even crispiness.
If using, sprinkle the grated Parmesan cheese on the asparagus during the last minute of cooking.
Once done, carefully remove the asparagus from the air fryer using tongs and serve immediately.