Preheat your oven to 350°F (175°C) and line a 9x9-inch baking pan with parchment paper, leaving an overhang for easy removal later.
In a medium bowl, combine the graham cracker crumbs and melted butter until the mixture resembles wet sand.
Press the crumb mixture into the bottom of the prepared baking pan to form an even layer. Bake for 8-10 minutes, or until lightly golden. Remove from the oven and let it cool.
In a large mixing bowl, beat the softened cream cheese until smooth using a hand mixer or stand mixer.
Add the pumpkin puree, granulated sugar, eggs, vanilla extract, pumpkin pie spice, cinnamon, and salt to the bowl. Beat on low speed until the mixture is well combined and creamy.
Pour the pumpkin cheesecake mixture over the cooled crust, spreading it evenly with a spatula.
Bake in the preheated oven for 25-30 minutes, or until the edges are set but the center still has a slight jiggle.
Remove from the oven and let the bars cool in the pan for about 1 hour at room temperature, then refrigerate for at least 2 hours or overnight for better texture and flavor.
Once chilled, lift the bars out of the pan using the parchment paper and cut them into squares.
Serve chilled, topped with a dollop of whipped cream if desired.