Mix the graham cracker crumbs and sugar in a bowl, then pour in the melted butter and stir until the mixture resembles wet sand.
Press the crumb mixture evenly into the bottom of a springform pan, creating a firm crust. Chill in the refrigerator for about 15 minutes to set.
In a mixing bowl, beat the softened cream cheese until smooth and creamy, using a spatula or hand mixer to eliminate lumps.
Add the sugar, pumpkin, vanilla, and cinnamon to the cream cheese, then gently fold or beat until fully combined and smooth.
In a chilled bowl, whip the heavy cream until stiff peaks form, then gently fold it into the pumpkin mixture to keep it light and airy.
Pour the filling over the chilled crust, smoothing the top with a spatula for an even surface. Cover with plastic wrap.
Refrigerate the cheesecake for at least 4 hours or overnight until set and firm to the touch.
Once set, remove the cheesecake from the springform pan and slice with a clean, sharp knife.
Serve slices with a dollop of whipped cream or a sprinkle of cinnamon for extra flavor.