Choose a round pan with a flat bottom and a tight fitting lid that will fit inside your pressure cooker. If you don't have a lid, any lid will do, even aluminum foil.
Generously grease the pan.
In a small bowl whisk the eggs and then blend in the melted and cooled butter along with the other liquid ingredients.
In a large bowl mix together the dry ingredients.
Add the liquid ingredients to the dry ingredients and stir until just BARELY blended. The batter should look a bit lumpy.
Pour the batter into the prepared pan, only filling to about 2/3 full to allow room for it to rise.
Add 2/3 cup of water to the pressure cooker and put a cooking rack or trivet in the bottom. Use foil helper handles to place the pan on top of the rack.
Lock the lid in place and bring to 15 psi over high heat, then immediately reduce the heat to the lowest possible setting to stabilize and maintain that pressure. Cook 22 minutes. Remove from heat and use the natural release method before opening lid.