Preheat the oven to 350°F. Line a 9x13-inch baking pan with parchment paper or foil.
Crush the graham crackers into fine crumbs using a food processor.
In a medium bowl, combine the graham cracker crumbs, brown sugar, melted butter, and salt. Press the mixture evenly into the bottom of the prepared pan.
Using a hand mixer, beat the softened cream cheese and sugar on high speed until light and fluffy.
Reduce the mixer speed to medium. Add the eggs one at a time, mixing well after each addition until smooth.
Spread half of the cheesecake mixture evenly over the crust.
Add the pumpkin puree and pumpkin pie spice to the remaining cheesecake mixture and mix until combined.
Carefully spread the pumpkin cheesecake mixture evenly over the plain cheesecake layer.
Bake uncovered for 40–45 minutes, or until the center is set and slightly firm.
Cool completely at room temperature, then refrigerate for at least 4 hours, preferably overnight.
Cut into bars and top with whipped cream before serving.