Spray a 7" springform pan with nonstick spray. In a small bowl, combine the ginger snap crumbs, pecans, sugar and butter. Spread evenly in the bottom of the pan and about 1/2" up the sides. Freeze for 10 minutes.
For cheesecake filling
In a large bowl, mix the cream cheese, and sugar at medium speed until smooth. Mix in flour, vanilla, pumpkin pie spice and salt until just blended. Add the eggs and mix again until just blended. Do not over mix!
Remove one cup of the batter to a small bowl and set aside. Add the pumpkin to the remaining batter in the large bowl and mix again until blended. Pour batter into crust.
Spoon the cup of plain cheesecake that was set aside on top of the pumpkin batter in the pan. Take a knife and swirl it through the batter back and forth to create a marbled effect.
Gently tap the pan on the counter to bring air bubbles to the surface. Pop these with a toothpick or fork and then smooth out the top with a spatula. Cover with foil. (This is not required, but I prefer to keep as much water off the top of the batter as possible, and for this size batter/pan it did not affect cooking time.)
Pour 1 cup water into the cooking pot and place the trivet in the bottom. Center the springform pan on a sling and carefully lower it into the cooking pot. Close and lock the lid, turning the steam release valve to closed. Select Beans/Chili and press Start/Stop. (High pressure, 20 minutes)
When the cook time ends, release pressure naturally for 10 minutes and finish with a quick pressure release. Carefully remove the pan with the sling and cool on a wire rack to room temperature. Recover with foil and place in the refrigerator for at least 4 hours (overnight is better.)
Take your time getting the air bubbles to come to the surfaceDab away any condensation with a paper towelUse a hand mixer, rather than a stand mixer to avoid over beating