Preheat oven to 350℉. Lightly grease a 9” x 13” cake pan or baking dish.
In a medium bowl whisk together the flour, powdered sugar and salt. With a pastry cutter or your hands cut the cubed butter into the flour mixture until it resembles wet sand. It will be very crumbly and dry, but that is ok.
Push the crust into the pan, and using a glass press the crust evenly into the bottom of the pan and slightly up the sides. Bake for 15-20 minutes, until lightly browned.
While the crust bakes, in a medium size bowl whisk together the flour, brown sugar and salt. Whisk in the eggs, corn syrup and vanilla extract until smooth.
Fold in the pecans. Pour mixture evenly over the baked crust and return to the oven for 25-35 minutes, or until the center is just set and no longer liquidy.
Cool completely and refrigerate until ready to cut and serve. Store in the fridge, tightly wrapped for up to 6 days.
If you do not cool the bars before cutting, you could risk the chance that the filling will not be set and it can squish out of the bars as you cut them. Similarly, underbaking the bars will make the filling too liquidy. The center of the bars should be set, and have a little jiggle like a jello. It will firm up more as it cools.
Notes
Use a pastry cutter to work the butter cubes into the flour mixture until it resembles wet sand. It will be very crumbly and dry, but that is ok.
Be sure the crust completely covers the bottom of the pan. Use the bottom of a flat object (like a drinking glass) to work the crust into the corners.
Avoid underbaking. Similarly, if you underbake your dessert bars, the filling will be too runny. The center of the bars should be set, and have a little jiggle, like Jello. It will firm up more as it cools.
Using a glass baking dish allows you to look at the bottom of the crust to determine if it is thoroughly baked.
Be sure to cool the bars completely. If they aren't completely cool before you start cutting, the pie filling may not be fully set. When this happens, filling can squish out of the bars as you cut them.