Spray a 7x3 springform pan with non-stick spray and set aside.
Add Oreo crumbs, melted butter, brown sugar, and nutmeg to a medium bowl and mix.
Transfer the crumb mixture to the springform pan and start to level out your crust (I like to use a measuring cup to make it flat).
Place the springform pan in the freezer for about 20 minutes while you are making your batter.
Beat softened cream cheese and sugar on medium until combined with a hand mixer.

Then add remaining ingredients and beat again until smooth, scraping down the sides to ensure everything is well combined.
Take pan out of the freezer and make a tinfoil “lid” that is loose at the top in case the cheesecake rises during the baking process, but along the sides to now allow excess moisture in. Remove this lid and set it aside.
Pour the batter on top of the crust and leave ¼ inch of space at the top, then put “lid” on the pan.

Place the trivet in the Instant Pot along with water, then carefully lower your springform pan in and secure the lid with the value closed.
Set your Instant Pot to high if you have it, or just in manual mode and put 50 minutes on the timer, then start.
Once complete, allow a 25-minute natural release of pressure before opening.
Put the cheesecake on a wire rack and remove the tin foil. Rest it for an hour, then loosen the edges with a sharp knife.

Set in the fridge for 6-8 hours still in the pan.
Once the cheesecake is fully set, remove and slice.