Preheat air-fryer to 400 degrees or preheat oven to 425 degrees.
Cut the zucchini in half, then in half again, then cut the halves into sticks (aka fries) ¼ to ½ inch thick and 3-4 inches long. Place on paper towels for a few minutes to get excess moisture out of zucchini.
To a small bowl, toss together bread crumbs and flour. Add to a dinner size plate and spread out. To another bowl add egg and beat well.
Dredge zucchini in egg and then in crumb/flour mixture and place on a plate or baking sheet. Lightly spray zucchini fries with cooking spray. Sprinkle with garlic salt.
To Bake in Air-Fryer: Spray the inside basket of the air-fryer with a little cooking spray. Working in batches, place zucchini fries in a single layer in the air-fryer. Place them close together but don’t overlap. Cook for 8-10 minutes, until crispy. If cooking in batches keep the first batch in a 300 degrees oven to keep warm and crisp. Add more garlic salt, if needed.
To Make in Oven: Follow the recipe as instructed above to prep. Preheat oven to 425 degrees. Line a baking pan with aluminum foil or parchment paper and lightly coat with cooking spray. Place zucchini fries on pan and bake for 25-30 minutes, turning once, until golden and crispy.
Serve at once. Zucchini fries are best when served fresh. They will become soft in texture as they cool down.