Preheat the oven to 325 degrees F. Place a large roasting pan on the lower third rack of the oven. Place a kettle of water on the stove to boil. Spray a 9-inch springform pan with nonstick spray. Wrap a double layer of heavy-duty foil around the bottom and up the sides of the pan.
In a large bowl, blend the cream cheese until smooth and creamy, about 1 to 2 minutes. Add the granulated sugar and salt, and blend for 2 minutes.
Add the eggs one at a time, blending after each addition. Mix in the sour cream, heavy whipping cream, and vanilla. Pour the batter into the prepared pan.
Set the cheesecake pan into the roasting pan in the pre-heated oven. Pour hot water into the roasting pan, surrounding the cheesecake pan.
Bake for approximately 45 minutes until set. Let cool on a wire rack for at least an hour, then freeze completely for 4 to 5 hours.
Preheat the oven to 350 degrees F. Spray two 9-inch round cake pans with nonstick spray and line them with parchment paper.
Combine oil and sugars using an electric mixer until well-combined. Add in eggs one at a time and mix in pumpkin puree.
In a separate bowl, whisk together the flour and remaining dry ingredients. Add dry ingredients alternately with buttermilk, beating well.
Divide the batter between the two pans and bake for 30 to 35 minutes until a toothpick comes out clean.
Cool the cake layers in the pans for 20 minutes, then turn them out to cool completely.
Combine the remaining cream cheese, pumpkin puree, spices, and vanilla for frosting. Add powdered sugar until reaching desired consistency.
Assemble the cake by placing one layer on a plate and spreading a small amount of frosting. Place the cheesecake layer on top, followed by the second cake layer and frost the entire cake.
Refrigerate until ready to serve; best after chilling a couple of hours or overnight.
