Things you need:
1 cup of flour for all purposes
½ cup of sugar
Cocoa powder, ¼ cup
1 tsp of baking powder
½ tsp of baking soda
A little bit of salt
1 egg
½ cup of milk
¼ cup of oil
1 tsp vanilla 
How to make it:
1. Mix the batter
Put the flour, sugar, cocoa powder, baking powder, baking soda, and salt in a bowl.
Put in the oil, milk, egg, and vanilla. Mix everything together until it’s smooth. Don’t mix too much; just until everything is mixed.
2. Get the pan ready
Use baking paper or grease a small cake pan that fits your air fryer.
3. Put it in
Put the batter in the pan and smooth out the top.
4. Fry in the air
Set the air fryer to 160°C (320°F).
Cook for 20 to 25 minutes, or until a toothpick comes out clean.
A little tip:
Just loosely cover the top with foil if it’s cooking too quickly. And after it’s done, let it cool down a bit. It will get even softer.