Adjust oven rack to the lower third position and preheat the oven to 350°F (177°C). Spray a 9-inch springform pan with nonstick cooking spray. Set aside.

Using a handheld or stand mixer fitted with a paddle attachment, beat the cream cheese and granulated sugar together on medium speed in a large bowl until smooth and creamy, about 2 minutes. Add the sour cream, vanilla extract, and flour and beat until combined. On low speed, add the eggs one at a time, beating after each addition until just blended. Do not over-mix the filling after you have added the eggs. Set aside.

In a medium bowl, whisk the oil, brown sugar, eggs, vanilla extract, and blotted-dry pumpkin (see notes) together until combined. In a large bowl, whisk the flour, baking soda, cinnamon, pumpkin pie spice, and salt together. Pour the wet ingredients into the dry ingredients and whisk until no large lumps remain. Avoid over-mixing the pumpkin cake batter.

Spread 1 and 1/2 cups of the pumpkin cake batter into the bottom of prepared pan. On top of the pumpkin batter, begin dropping large spoonfuls of both the cheesecake batter and pumpkin batter, alternating one after the other. It doesn’t have to be neat or perfect. Do not swirl with a knife. See photo above of what my cake looked like before going into the oven.

If needed for extra visuals, see my How to Make a Cheesecake Water Bath; the visual guide will assist you in this step. Boil a pot of water. You need 1 inch of water in your roasting pan for the water bath, so make sure you boil enough. I use an entire kettle of hot water. As the water is heating up, wrap the aluminum foil around the springform pan. Place the pan inside of a large roasting pan. Carefully pour the hot water inside of the pan and place in the oven. (Or you can place the roasting pan in the oven first, then pour the hot water in. Whichever is easier for you.)

Bake for 65-75 minutes or until the center is almost set.* If you find the edges are browning, loosely place aluminum foil on top of the cake as it bakes. Once done, turn the oven off and open the door slightly. Let the cheesecake sit in the oven in the water bath for 1 hour. Remove from the oven, peel the aluminum foil off the bottom, wipe pan dry with a towel, then place in the refrigerator to chill for at least 6 hours or overnight (preferred).

After chilling, run a knife around the edge of the cake to loosen it from the rim. Remove the rim.

(This can be made up to 2 days in advance – cover and store in the refrigerator until ready to use.) Using a handheld or stand mixer fitted with a paddle attachment, beat the cream cheese and butter together on medium-high speed in a medium bowl until smooth and creamy. Add the confectioners sugar, vanilla, and salt. Beat on low speed for 30 seconds, then turn up to high speed and beat until smooth and creamy. Beat in 1-2 Tablespoons of milk, depending how thick or thin you want the frosting. Spread onto chilled cheesecake. Top with pecans, if desired.

Cut into slices and serve cheesecake chilled. Cover leftover cheesecake and store in the refrigerator for up to 4 days.