Mix graham cracker crumbs, melted butter, and sugar until it’s like wet sand. Use a food processor if you have one—pulse graham crackers, melted butter, and sugar together.
Press the mixture into a springform pan to create an even layer. Refrigerate to set while you prep the filling. Optionally, bake the crust at 350 degrees for 7 minutes.
In a large bowl, beat cream cheese, brown sugar, vanilla, and powdered sugar until smooth (about 4 minutes). Scrape the bowl to ensure even mixing.
Gently fold in pumpkin puree and spices until smooth.
In a separate bowl, whip heavy cream until peaks form. Fold it into the pumpkin-cream cheese mixture without deflating the whipped cream.
Spoon the pumpkin-cream cheese mixture over the crust evenly.
Chill the pumpkin no-bake cheesecake for at least 4 hours, preferably overnight, to let the flavors meld and the texture set.
Before serving, top it with a generous layer of whipped cream. Optionally, add a dash of cinnamon sugar or a drizzle of salted caramel.