Mix together all 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 smoothly into the pan
Bake at 300 degrees for 22 - 25 minutes, until 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 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 for 30 - 35 minutes, until set and hardly jiggly in the center. The edges should be browned
Remove the pecan pie bars from oven and allow to cool completely
Refrigerate for 30 minutes, then cut into slices