Mix together all of the ingredients for the crust: flour, butter, brown sugar, salt, and vanilla, until combined.
Line an 8 X 8 baking dish with parchment paper.
Use your hands to press the shortbread crust batter evenly into the pan.
Bake the crust at 300 degrees for 22-25 minutes, or until the edges are golden and beginning to brown.
In a large bowl, mix together the pecan pie bar filling: the eggs, maple syrup, brown sugar, heavy whipping cream, flour, vanilla, and salt.
Once that is mixed, stir in the pecan pieces.
When the shortbread crust is done baking, pour the pecan pie bar filling over the top.
Turn the oven up to 350 degrees and bake the pecan pie bars for 30-35 minutes, until they are hardly jiggly in the center. The edges should be browned.
Remove the pecan pie bars from oven and allow them to cool completely.
Refrigerate the pecan pie bars for 30 minutes, then cut into slices.