Combine dry ingredients in a bowl: Flour, Baking Soda, Baking Powder, Salt, Sugar, and Cocoa Powder.
Add the wet ingredients: Egg, Oil, Milk, and Vanilla and mix.
Add in boiling water and mix again.
Pour batter into 6 inch circular pan (or 7 inch circular pan / bunt pan).
Open Instant Pot. Add 1 cup of water, place trivet, then pan into the Instant Pot liner.
Close Instant Pot. Select manual for 40 minutes
When done, NPR (natural pressure release - wait for the pressure to release naturally once done).
(Optional) Decorate cake with icing, ganache, chocolate, fruits, etc.