Preheat the oven to 300 degrees F. Line the bottom of an 8 x 8 baking pan with parchment paper with the sides sticking up and over the edges so you can easily pull the pecan pie bars out of the baking dish to cut.
In a small bowl, mix butter, brown sugar, vanilla, and flour until you have a thick well incorporated dough.
Press into the bottom of the prepared baking dish in a single and bake at 300 degrees F for 12-14 minutes.
In a large bowl, mix eggs, brown sugar, corn syrup, almond extract, and flour until combined. Fold in chopped pecans.
When the shortbread layer is done cooking, remove from the oven and pour your pecan mixture over the top. Raise the oven temperature to 350 degrees, and bake again for 30-32 minutes or until the top is golden and crispy, and the middle is set.
Take out of the oven and allow to cool completely to room temperature. These slice up nicely if completely room temperature.
Lift the pecan pie bars out of the baking dish, cut, and serve!