Preheat the oven to 350 F. Add the graham crackers to a food processor and pulse until crumbs. Add melted butter, sugar, and salt and pulse until combined.
Dump the mixture into a 9x13" pan lined with parchment paper. Press the mixture evenly on the bottom of the pan. Transfer to the oven and bake for 5 minutes. Let the crust cool while you make the blondies.
To make the blondies, add the butter to a pan over medium heat. Stir while the butter melts. Continue to stir for about 5 minutes -- the butter will begin to bubble, then foam, then the foam will subside. When the foam subsides, you'll be left with brown, nutty smelling butter. Remove the pan from the heat and let it cool for at least 10 minutes.
Once the butter has cooled slightly, add the brown sugar and stir until combined. Add the eggs, one at a time, stirring between each addition. Add the pumpkin puree and vanilla and stir until combined.
Add all the dry ingredients and stir until just combined. Pour the batter on top of the cooled graham cracker crust. Transfer to the oven and bake for 30-40 minutes until the middle is just set (and no longer jiggles). Remove from the oven and let cool completely (if you are in a hurry, you can stick the blondies in the fridge to speed up the cool time).
While the blondies cool, make the cheesecake layer. Add the cream cheese to a bowl and mix with a hand mixer for 4-5 minutes. Add sugar, pumpkin pie spice, and vanilla and mix until sugar is totally incorporated, about 2 minutes.
In a separate bowl, add the heavy cream and whip until stiff peaks form. Transfer the whipped cream into the cream cheese mixture and fold in until smooth. Pour the cream cheese mixture onto the blondies and spread out evenly. Cover with plastic wrap and transfer the fridge for at least 4 hours or overnight.
Once the cheesecake layer has set, slice with a large knife and dust the top with a little pumpkin pie spice. Serve and enjoy!