Preheat oven to 350 degrees. Prepare baking sheet or pan: with spray or butter, parchment paper bottom and flour. Prepare shortbread: Melt butter. In one bowl, add the melted butter to the rest of the ingredients in the recipe.
Mix shortbread ingredients until combined.
Use your hand to combine. It will be pliable and easily manipulated onto the bottom of your prepared baking sheet or pan.
Once you have it covered, use a fork to poke little holes throughout the dough. Bake dough for 10 minutes. While it bakes, prepare the pumpkin pie custard.
This can all be hand-whisked in a single bowl. First, place the sugar, cornstarch and salt in a bowl, and top with the eggs and pure vanilla extract.
Whisk these ingredients together until smooth.
Add the cinnamon, nutmeg, ginger and cloves and whisk.
Add in all that glorious pumpkin.
You guessed it. Whisk it all together.
Last, add the evaporated milk and whisk.
The pumpkin custard batter will be smooth and ready to pour.
Pour all of the batter onto the top of the pre-baked shortbread.
Bake at 350 for 45-50 minutes, or until it has baked-through and your tester comes clean at the center. It will not crack. It will not deflate. It will maintain the beautiful height and firmness.
Once the pan has completely cooled, use a sharp knife and cut bars. Keep at room temperature for the day, or my suggestion is to refrigerate. Serve as-is, or with whipped cream. These will be good for up to four days, but good luck keeping them around for that long!
The cornstarch is the ingredient that allows for the firmness without compromising flavor or texture. What we have here is basically pumpkin pie to-go. Enjoy!