Preheat your oven to 350F. Line a 9x13" baking pan with parchment paper, leaving enough of an overhang on the sides to easily lift out the completed bars. Set this aside.
In a food processor, pulse the graham crackers and pecans together until they turn to crumbs. Then add in the granulated sugar and melted butter and continue to pulse until everything is moistened and combined.
Place the crust mixture into the prepared baking pan and pack it down tightly and evenly over the bottom. Place in the oven and bake for 8 minutes. Once it's done remove from the oven and set it aside until your ready with the pie filling.
For the filling, place the pumpkin puree, brown sugar, eggs, heavy cream, vanilla extract, cornstarch, pumpkin pie spice, cinnamon, salt and pepper in a large mixing bowl. Use a hand mixer fitted with a whisk attachment to quickly whisk it all together until combined.
Pour the pie filling evenly over the top of the graham cracker crust. Place it in the oven and bake for 40-50 minutes, or until the center is no longer jiggly.
Place the baking pan on a cooling rack and let it sit until it has cooled completely. Once it's cool, cover it and transfer it to the fridge to chill for at least 1 hour and up to 3 days.
Once chilled and you're ready to serve, remove the pan from the fridge and lift the parchment paper out of the pan. Slice into squares and serve. Leftovers can be stored for up to a week covered in the fridge.
