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.
Prepare the vegan chocolate ganache (recipe below).
In a large bowl, whisk together the granulated sugar, brown sugar, coconut yogurt, almond milk, oil and apple cider vinegar until smooth. It should take about a minute. Then mix in the vanilla and whisk to combine.
In a medium bowl, mix together the flour, cocoa powder, baking powder and salt. Gradually add half of the flour mixture to the wet mixture and use a wooden spoon to mix until almost smooth. Repeat with remaining flour and add the boiling water. Mix again until the batter is smooth and thick. Fold in the chopped chocolate or chocolate chips with a rubber spatula.
Pour the batter into the prepared springform pan.
Pour 1 cup of water in the inner pot of the Instant Pot and add the steamer basket or trivet with the legs facing up.
Carefully place the springform pan on top of the steamer basket/trivet. Seal the Instant Pot lid and hit the Manual button. Set to High Pressure and cook for 30 minutes. Make sure the Venting Knob is set to the Sealing position (as opposed to the Venting position).
When the 30 minutes is over, select the Cancel setting on the Instant Pot for a natural pressure release. After 10 minutes, switch the Pressure Release knob from Sealing to Venting to release any remaining steam.
Using oven mitts, carefully remove the springform pan by grabbing onto the steamer basket legs. Let the cake cool slightly for 10 minutes.
Carefully unclasp the springform pan and use a spatula to transfer the cake from the parchment paper onto a cutting board or cake pan. Spread with the vegan chocolate ganache.