Start by heating a large pot of water until it's boiling vigorously. Put the gizzards into the boiling water and let them cook for 30 minutes. Then, take the gizzards out of the pot and carefully drain them.
Mix together flour, seasoned salt, black pepper, garlic powder, paprika, and cayenne pepper in a shallow plastic container. Close the lid tightly and shake the container well to blend the ingredients thoroughly. Put the gizzards into the seasoned flour, close the lid tightly again, and shake it to coat the gizzards evenly with the mixture.
Take a small bowl and put the beaten egg in it. Dip each gizzard into the beaten egg, making sure it is coated, and then put it back into the seasoned flour. Close the lid tightly and give it one final shake to coat the gizzards again. Allow them to sit for 5 minutes before proceeding.
Meanwhile, preheat the air fryer to 400 degrees F (200 degrees C).
Put the gizzards in the basket of the air fryer. Spray the tops of the gizzards with cooking spray to coat them.
Cook them for 4 minutes. After 4 minutes, shake the basket to ensure even cooking and spray more cooking spray on any areas that appear dry. Put the basket back into the air fryer and continue cooking for an additional 4 minutes.
Serve immediately and enjoy!