Short Answer:

To achieve even crispiness when cooking frozen foods in an air fryer, arrange items in a single layer with space between them, cook at the recommended temperature (usually 180–200°C), and flip or shake halfway through.

Using a light spray of oil can enhance browning, and preheating the air fryer ensures immediate heat circulation. Following these tips ensures frozen items like fries, nuggets, and spring rolls cook evenly, producing golden, crispy exteriors while keeping the interiors tender.

Detailed Explanation:

Tips for Achieving Even Crispiness

Proper Arrangement
Arrange frozen foods in a single layer in the air fryer basket. Avoid stacking or overcrowding, as this blocks hot air circulation. Spacing each piece allows heat to reach all surfaces, ensuring even browning and consistent texture throughout the batch.

Correct Temperature
Cooking at 180–200°C (360–400°F) promotes crispiness without overcooking. Lower temperatures may leave food soft or soggy, while excessively high temperatures can burn the exterior before the interior is heated. Maintaining the right temperature balances crispiness with thorough cooking.

Shaking or Flipping Midway
Flipping or shaking food halfway through cooking redistributes pieces and exposes all sides to hot air. This prevents uneven browning and ensures each piece develops a uniform golden, crispy exterior. This step is especially important for fries, breaded items, and stuffed snacks.

Optional Light Oil Spray
A small spray of oil can enhance browning and promote a crunchy texture. Only a minimal amount is needed, as the air fryer circulates hot air effectively. Overuse of oil may make food greasy and reduce crispiness.

Preheating the Air Fryer
Preheating the air fryer for 2–3 minutes ensures that the basket reaches the desired temperature before adding frozen food. This allows immediate and even heat exposure, which helps the outer layer crisp quickly while cooking the interior evenly.

Choosing Suitable Foods
Firm, low-moisture vegetables and coated frozen items crisp best. Foods with high water content or uneven thickness may require extra time or spacing adjustments to achieve uniform crispiness. Cutting items into uniform sizes can help improve consistency.

Monitoring and Adjusting Cooking Time
Check food a few minutes before the recommended cooking time ends. Remove items once they are golden and crispy, and adjust for batch size or thickness. Overcooking can dry out the interior, while undercooking may leave the exterior soft.

Conclusion:

Achieving even crispiness in frozen foods requires proper spacing, correct temperature, flipping or shaking midway, optional light oil, preheating, and selecting appropriate foods. These steps ensure golden, crunchy exteriors and tender interiors for fries, nuggets, vegetables, and snacks. Consistently following these tips produces evenly cooked and visually appealing air-fried foods.