Preheat your oven to 350 degrees F. Line a 13x9 pan with parchment paper. Make sure the paper comes up onto the sides of the pan. This will help you lift the bars out after they're cooled. Do not try to bake these in the pan without the parchement paper. They will stick!
In a food processor, add the flour, sugar, cinnamon, and cold , cut up butter. Pulse a few times. It will look like a sandy mixture. It will not come together and doesn't need to be pulsed more than a few (6-8) times.
Pour your flour mixture into your parchment lined pan. Evenly spread the mixture onto the bottom. Again, this mixture isn't suppose to hold itself together. Just make sure it's even and slightly packed into the pan.
Place your pan with the crust into the oven for 20 minutes. While it's baking, start your Pecan Pie top layer.
For the Pecan Pie top layer:
In a medium sized bowl, add your chopped pecans, dark & light corn syrup, eggs, brown sugar, flour, salt, and vanilla.
Whisk these together. It will seem thick and like it's not going to all incorporate. Use a little elbow grease and I promise it will!
Set this mixture aside while the bottom layer finishes baking.
Once the bottom layer is done, remove from the oven and immediatly pour your Pecan Pie mixture onto it.
Place it back into the oven for 40-46 minutes. It should be set in the middle. It will also set a bit more while it cools.
Remove from the oven and let cool completely in the pan.
Once completely cooled, lift the bar out of the pan using the parchment paper. My parchment paper didn't go far enough above the bars, so I ran my knife around the edge of the pan to make sure it wasn't going to stick.