Crush graham crackers using a plastic bag and a rolling pin (or a food processor if you have one).
Stir in sugar, and melted butter.
Grease a 9 inch cake pan or springform pan. Press graham cracker mixture into the bottom. Refrigerate for ~30 minutes or until set.
In a large bowl, mix cream cheese, brown sugar, and white sugar until light and smooth.
Stir in pumpkin, vanilla, and pumpkin pie spice until fully combined.
Whip heavy cream until stiff peaks form. (I used an ice cold bowl/whisk, but a mixer would work as well).
Fold into pumpkin cheesecake mixture.
Spread evenly into graham cracker crust.
Refrigerate for 2-3 hours or until set.
Garnish with additional whipped cream if desired.