Generally cook your food items in one layer Except if the recipe states that stacking is alright (like in these air fryer French fries and sweet potato fries recipes) Air fryers cook food items rapidly and evenly, because of the concentrated warmth supply. The air fryer was invented by Philips https://mylesbkhgr.wssblogs.com/30133933/a-secret-weapon-for-cook-companion-air-fryer