In a medium size dry skillet, add the pecans and roast over medium heat stirring constantly, for 3-4 minutes or until fragrant. Remove from heat and set aside.
In a food processor, add the gingersnap cookies and pecans. Pulse until fine crumbs form.
Add in the salt, cinnamon, and melted butter and pulse until well combined.
Prepare a 7” springform pan (I used the Instant Pot version) with nonstick spray. Pour the crumbs into the pan and using a clean hand or spoon press the crumbs to form the crust taking it about 1/3 of the way up the sides of the pan.
Place in the freezer while you prepare the filling.
Add the softened cream cheese into the bowl of a stand mixer equipped with a paddle attachment. Turn the mixer to high speed and mix for 5-6 minutes scraping the sides every 2 minutes.
Scrape down the sides and bottom of the bowl and add the granulated sugar and vanilla. Mix on medium speed until well combined.
Scrape down the sides and bottom of the bowl and add the sour cream and eggnog. Mix on low speed until well combined.
Add in cinnamon and nutmeg and mix until incorporated.
With the mixer on a low speed, add the eggs one at a time, mixing well between each addition. Make sure to scrape the bowl after both eggs are incorporated and mix on low for about 1 minute. NOTE: Be very careful not to overmix here. You want to mix just enough to make sure the eggs are incorporated well.
Remove the crust from the freezer and pour in the cheesecake filling. Gently tap the cheesecake on the counter 5-6 times to remove any air bubbles.
Cover the top of the springform pan in aluminum foil being sure to seal the top of the pan well.
Pressure Cooking the Cheesecake
Add 1 cup of water and a trivet into a 6-quart Instant pot.
Place the cheesecake on the trivet and place the lid on sealing.
Set Instant Pot to HIGH PRESSURE for 40 minutes. After cooking completes, allow a NATURAL RELEASE.
Once you can open the lid, carefully remove the cheesecake and place on a wire rack and allow to cool to room temperature.
Once the cheesecake has cooled, place in the refrigerator for at least four hours but best overnight.
Remove the cheesecake from the springform pan, slice and place on a serving dish. If using the optional toppings: spoon approximately ½ cup rum sauce over top of the cheesecake and smooth. Top with whipped topping and using a small sifter, sprinkle ground nutmeg on the top.
CREATING A FOIL SLING (optional but recommended):Using a sling makes it easier to lower the cheesecake into the Instant Pot and remove it after cooking completes.
Create a foil sling using a 20-inch piece of foil folded in thirds vertically.
Center the pan on the middle of the sling and lower it into the Instant Pot onto the trivet.
Fold the ends of the sling over as needed to allow locking the Instant Pot lid, keeping them pressed outward to the walls of the Instant Pot insert; do not fold them onto the top of the pan.