In a small bowl, combine the crushed lady fingers, espresso, Kahlua and melted butter.
In a large bowl, combine the cream cheese, granulated sugar and mascarpone cheese with a hand mixer until smooth.
Add the eggs, powdered sugar and vanilla.
Mix until combined.
Butter the bottom of a 8 inch spring form pan.
Press the ladyfinger mixture into the bottom. (no need to go up the sides)
Pour the cheese mixture on top of the crust and smooth out evenly.
Cover the pan with a paper towel and seal with a piece of aluminum foil.
Pour the water into the pressure cooker pot.
Use a foil sling and the trivet to lower the cheesecake into the pressure cooker pot.
Place the lid on and turn to locked position.
Turn the steam release valve to sealing.
Press the manual button and adjust the time for 25 minutes.
After the pressure cooker has finished cooking and the timer has counted to zero, allow the steam to naturally release for 10 minutes.
Carefully release any remaining steam and remove the lid.
Take the cheesecake out and uncover.
The center of the cheesecake will move slightly when the pan is gently shaken.
It will become firm once it is cold.
Allow to cool completely before placing in refrigerator to chill.
Chill for at least 4 hours up to two days.
Remove the spring form pan ring by releasing the latch.
Dust the cheesecake cake and serving dishes with cocoa powder, slice and serve.