For the crust:
• 1 1/2 cups graham cracker crumbs
• 8 tablespoons (1 stick) unsalted butter, melted
• 1/4 cup sugar
For the filling:
• 4 (8-ounce) packages cream cheese, softened
• 2 1/2 cups sugar
• 1/3 cup sour cream
• 1 (15-ounce) can pumpkin purée
• 6 large eggs, at room temperature, lightly beaten
• 1 tablespoon vanilla
• 2 teaspoons ground cinnamon
• 1 teaspoon ground ginger
• 1 teaspoon kosher salt
To make the crust: Heat the oven to 350 degrees. Lightly spray the bottom and sides of a 9- by 3-inch round cake pan with nonstick oil spray. Line the bottom of the pan with a circle of parchment paper and lightly spray the paper with additional nonstick oil spray. Line a roasting pan with a kitchen towel.
In a large bowl, stir together the graham cracker crumbs, butter and sugar until the butter is thoroughly incorporated and mixture has the consistency of wet sand. Pour the crust mixture the prepared pan and use the back of a measuring cup and your hands to evenly and tightly pack the crust mixture onto the bottom of the pan. Bake until lightly browned, 10 to 12 minutes. Let cool to room temperature. Lower the oven temperature to 250 degrees.
To make the filling: Bring a medium saucepan of water to a simmer. Keep warm.
Using an electric mixer or a stand mixer fitted with the paddle attachment, beat the cream cheese on medium-high speed until soft and fluffy, about 45 seconds. Add the sugar and sour cream and continue to beat on medium-high until smooth and well-combined, 30 to 45 seconds. Reduce the speed to medium-low and beat in the pumpkin, eggs, vanilla, cinnamon, ginger and salt until smooth, scraping down the paddle and sides of the bowl as needed, 1 to 2 minutes.
Pour the filling on top of the cooled crust. Place the cake pan inside of the prepared roasting pan.
Pour the simmering water into the roasting pan, two-thirds of the way up the outside of the cake pan. Bake until the sides of the cheesecake are set but center is still loose, about 2 hours.
Turn the oven off, then open the oven door for 1 minute to release some of the heat. Close the oven door and keep cheesecake in the cooling oven until the cheesecake jiggles only slightly when touched, about 1 hour.
Let the cheesecake cool at room temperature for at least 30 minutes before serving.
To serve, run a hot knife around the inside edges of the pan. Invert the pan onto a round plate or cardboard cake round. Remove the parchment paper from the bottom of the crust and invert the cheesecake back onto another plate or cardboard cake round. Slice and serve.