Use the bottom of a 7 inch springform pan to trace a circle on a piece of parchment paper. Cut the parchment paper into the circle shape and use as a liner for the springform pan. Spray the sides of the springform pan with cooking spray or lightly grease with oil.
For dry ingredients
Sieve and Mix all dry ingredients (All purpose flour, cocoa powder, baking soda , baking powder and salt) except sugar in a bowl abd keep aside.
Add vinegar to milk and let it stand for a few minutes.
Add granulated raw sugar to milk and vinegar mixture and whip until the sugar is almost melted.
Add in oil. Whip the liquid ingredients until oil is completely blended.
Pour the liquid mixture over the dry ingredients - whip with a spatula utill the batter is smooth and no lumps. Don't over beat!
Pour the batter in the pan .
Pour 1.5 cups of water to the inner pot
Place the pan over the silicone trivet. Cover the pan with foil and carefully place it inside the pot.
Seal the Instant Pot lid and hit the Manual button. Set to High Pressure and cook for 40 minutes.
When the 40 minutes is over, select the Cancel setting on the Instant Pot for a natural pressure release. After 10 minutes, release any remaining steam.
Carefully open the IP and lift the cake out using the silicone trivet handles.
Uncover the cake and let it cool in the pan for 10 minutes.
Now run a butter knife around the cake circumference and invert the cake on cooling wire rack.
In a saucepan or skillet, heat the coconut milk over medium heat until just simmering.
Meanwhile, place the chopped chocolate or chocolate chips in a medium heat-proof bowl. Pour the steamed coconut milk over the chocolate and let sit for 2 minutes. Then whisk until completely smooth and chocolate has melted.
You can use the ganache now if you prefer a more traditional liquid ganache texture. Alternatively, if you want a thicker texture more like a frosting, let the ganache sit for 1-2 hours and whisk occasionally, until it thickens and slightly hardens.