If using fresh green beans, trim the ends and cut them into smaller pieces if desired. Pat them dry with a paper towel to remove any moisture.
In a bowl, whisk together the all-purpose flour, cornstarch, baking powder, salt, pepper, and garlic powder.
Coat each green bean by dipping it first into the flour mixture, followed by the egg mixture, and then the breadcrumb mixture.
Preheat the air fryer to 375°F (190°C). Lightly spray the air fryer basket with cooking spray or brush with a little oil. Arrange the coated green beans in a single layer in the basket, leaving space between them for even cooking. Air fry for 8-10 minutes, shaking the basket halfway through, until the green beans are golden brown and crispy.
Once crispy, remove the green beans from the air fryer. Optionally drizzle with soy sauce or serve with your favorite dipping sauce. Enjoy these crispy green beans as a tasty appetizer or side dish!