Cut off pointy stem end of the onion, then peel.
make 4 downward cuts to form a double cross pattern, do not cut all the way through
Soak the onion in a bowl of water for later use
Whisk egg in a large bowl, mix with milk.
In a separate bowl, pour in all-purpose flour, add Oregano, sugar, salt, paprika powder, and baking powder, mix well
Place the onion inside the egg mixture, full coat the onion, then place it into the flour mixture, thoroughly coat it.
Repeat the steps, coat the onion with egg mixture and flours again.
Place the onion in a frying basket,
adjust the onion into a blooming position, evenly spray on sufficient amount of oil.
Let the blooming onion goes into the air fryer, to cook for 130 minutes at 170°C. Serve right away.