Make the crust first. Stir together the graham cracker crumbs, granulated sugar, and melted butter in a medium bowl until the crumbs look like wet sand and hold together when you press a pinch between your fingers. Press the mixture firmly and evenly into the bottom and about 1 inch up the sides of a 9-inch springform pan. Use the flat bottom of a measuring cup to press it tight. Refrigerate the crust while you make the filling.

Pour the cold heavy cream into a large clean bowl and beat with a hand mixer or stand mixer on high speed until stiff peaks form, about 3 to 4 minutes. The cream should hold a firm peak when you lift the beater. Set the bowl aside in the refrigerator.

In a separate large bowl, beat the room-temperature cream cheese on medium speed until completely smooth, about 2 minutes. Stop and scrape down the sides of the bowl at least once. If you see any lumps at this stage, keep beating. Lumps will not smooth out once the pumpkin is added.

Add the pumpkin puree, powdered sugar, cinnamon, nutmeg, ginger, and vanilla to the cream cheese. Beat on medium speed until everything is combined and the filling is a smooth, even orange color, about 2 minutes. Scrape the bowl again and give it one final mix.

Remove the whipped cream from the refrigerator. Using a rubber spatula, fold it into the pumpkin cream cheese mixture in two or three additions. Use a gentle folding motion, sweeping from the bottom up and over. Do not stir. You want to keep the air you whipped in so the filling stays light and sets firmly.

Spoon the filling into the chilled graham cracker crust and spread it into an even layer with the spatula. Smooth the top as best you can. Cover the pan with plastic wrap and refrigerate for at least 4 hours. Overnight is better and gives you the cleanest slices.

When ready to serve, run a thin knife around the inside edge of the springform pan before releasing the latch. Lift the ring off carefully. Slice with a sharp knife wiped clean between cuts. Serve with a dollop of whipped cream if you like.