Preheat air fryer: Preheat your air fryer to 375°F for 3–4 minutes
Toss with oil and seasoning: Place the frozen 16 ounces frozen shredded hash browns in a large bowl. Drizzle with 1.5 tablespoons olive oil or avocado oil and add 0.5 teaspoons garlic powder, 0.5 teaspoons salt, plus more to taste, and 0.3 teaspoons black pepper. Toss thoroughly until every shred is evenly coated. Do not skip this step — it is the secret to crispy results.
Spread in basket: If your basket has large holes, add a perforated parchment liner after preheating. Spread the seasoned hash browns in an even layer no deeper than ¾ inch. Press down lightly with a spatula.
Air fry — first stir: Air fry at 375°F for 5-6 minutes, then open the basket and stir to expose fresh surfaces to the hot air and release steam from the bottom.
Air fry — second stir: Continue cooking for another 5-6 minutes, then stir again. At this point, lightly spray the top of the hash browns with 1 teaspoons cooking spray (for finishing) for maximum crispiness.
Finish and serve: Cook for a final 5–6 minutes, until deeply golden and crispy. Total time: 17–20 minutes. Taste and adjust seasoning, then serve immediately — shredded hash browns are at their crispiest right out of the air fryer.