• Preheat the oven to 350 F. Line an 8x8 square baking pan with parchment paper so all sides are covered (two overlaying sheets).

Make the shortbread

• (I use a food processor for this part but you can also use a hand mixer) Add the flour, sugars, salt, and pumpkin spice to the bowl of a food processor and pulse to just mix the dry ingredients together. Stop the machine and slice the butter and add it to the bowl. Run the processor on high until the dough starts to clump together, about a minute or two.
• Press about two thirds of the dough into the bottom of the prepared pan. Use an offset spatula or floured measuring up to pack in the dough into an even layer. This will be the bottom crust (we pre-bake it so it’s not doughy later). Bake for about 25 minutes, until golden.

Make the filling

• While the crust is baking, start making the filling: set the softened cream cheese and brown sugar in a bowl and beat with a hand mixer until smooth (if you start to get lumps it’s because the cream cheese was too cold - warm the mix just a bit and proceed). Add the spices, vanilla, and salt and beat to combine. Beat in the pumpkin puree, and once beaten add the eggs and beat to combine. Lastly, beat in the powdered sugar.
• Once the crust has turned golden and baked for 25 minutes, pour the filling over it - smooth it over until it’s in an even layer. With the last third of the shortbread dough, add it in bits over the filling to distribute it all over, leaving some bits of exposed filling (see photos for reference). Return to the oven to bake until the top shortbread bits are golden brown, for about another 30 minutes. Let cool at room temperature. The bars are easiest to slice when cold. Enjoy warm, at room temperature, or set in the fridge and enjoy the bars cold the next day.