Melt the butter and crush the graham crackers. You can use a food processor or even just put them in a gallon storage bag and use a rolling pin to crush them.
Add the ¼ teaspoon pumpkin pie spice and the 1 tablespoon brown sugar to the graham cracker crumbs. Pour the crumb mix into the melted butter and stir well.
Pack the graham cracker mix as tightly as you can into the bottom of the springform pan and set aside.
Be sure your cream cheese, yogurt (or sour cream) and eggs have sat out at room temperature for at least an hour before mixing.
Cream the cream cheese for about 1 minute using a mixer (preferably a hand mixer) or until smooth.
Add in the brown sugar and beat again for about 1 minute.
Add in the vanilla and yogurt. Mix until incorporated, about 20-30 seconds.
Add in the eggs one at a time. Beat each egg in for about 10 seconds and scrape the sides of the bowl down before adding each one. Do not over whip the eggs. Take a spatula and gently stir the egg in if it needs more mixing.
Scoop 1½ cups of the cheesecake filling (about half) over the crust and smooth out evenly.
Mix the pumpkin puree, pumpkin pie spice and flour together in a small bowl. Add into the remaining filling and gently stir with a spatula or spoon.
Pour the pumpkin layer on top of the first layer.
Pour 1 cup of water into the Instant Pot. Place the springform pan into a silicone sling or make a foil sling.
If using a silicone sling, place it into the Instant Pot now. If using a foil sling, you need to put the trivet that came with your IP in first followed by the foil sling and your cake.
Cook on high pressure for 27 minutes and allow to do a natural release. As soon as it is done releasing, remove the cheesecake and blot any moisture that has accumulated on the top with a paper towel. Little drops are ok, but get any excess puddles of moisture off.
Cool on the counter for about 1 hour before placing in the fridge. Cool in the fridge for at least 3-4 hours before covering to prevent excess moisture. Then cover and allow it to cool in the fridge over night for best texture.
Nutritional values are estimated and so are the serving sizes.Plain yogurt or plain sour cream work great, either can be used.If freezing the cheesecake, allow to cool completely in the fridge and it is recommended to cut into slices before freezing. Wrap in plastic before wrapping in foil and use within 1-2 months.