Preheat oven to 350 degrees. Combine Shortbread Crust ingredients in a food processor, adding butter one piece at a time until a dry dough forms. (you can also cut in butter with a fork). Be careful not to over mix. The dough should be crumbly.
Press Shortbread Crust dough into an 8x8 parchment lined baking dish. Bake for 12 minutes. Let rest 3 minutes before pouring the pumpkin pie filling on top.
Pumpkin Pie Filling:
Combine all Pumpkin Pie Filling ingredients in a bowl and mix well, ensuring there are no lumps. Pour mixture on top of the HOT shortbread crust and bake for 50-60 minutes, or until center is barely jiggly and batter no longer appears wet on top.
Pecan Topping:
While pie bars are cooking. Heat the Pecan Topping ingredients in a sauce pan over medium heat until butter is fully melted and sugar starts to caramelize; about 3-4 minutes.
Once pie bars are done baking, pour pecan topping on top, return to oven and bake another 20 minutes.
Remove and let cool fully. Refrigerate 3 hours or overnight. Remove from pan and slice into bars. Serve with whipped cream if desired.
Notes
Be sure to use cold butter when making the short bread crust - cut it in with a fork or just pulse a food processor until combined. Be careful not to over mix or the butter will melt;
The pecan caramel topping can be omitted if desired, however, I think it's one of the best parts of this recipe!
The pumpkin filling should only jiggle a little when done and no longer looks wet on top - it will continue to set as it cools.
The pumpkin pie filling can be made a couple days ahead of time if desired. Store in an airtight container in the fridge until you're ready to use it.