Position a rack in the center of the oven and preheat the oven to 375 degrees F. Spread the pecans on a baking sheet and place them in the center of the oven. Toast until beginning to color, about 8 – 10 minutes. Remove the pecans from the oven, cool, and roughly chop them. Reduce the oven temperature to 350 degrees F.
Sift together 2 cups flour, cornmeal, 1/2 cup sugar, and a small pinch salt. Add 8-oz. (1 cup, or 2 sticks) of the butter and work it into the flour until it forms a smooth dough. You may do the first part of this step in a food processor fitted with a steel blade. Put in the flour, meal, sugar, and salt and pulse several times to sift. Add the butter and process until the mixture resembles coarse meal. Turn it out into a mixing bowl and finish blending the dough by hand. Wrap and chill for 30 minutes, or until manageable.
Press the dough in a 9″ x 13″ sheet cake pan in a uniform layer over the entire surface and press slightly up sides. Lightly prick it with a fork and place it in the center of the oven. Bake for 20 minutes, until it is beginning to color, then remove it from the oven and let it cool slightly.
Melt the remaining butter and let it cool slightly. Beat together the butter, eggs, remaining granulated sugar, brown sugar, and a small pinch of salt. Stir in the bourbon and pecans. Sift the remaining tablespoon of flour into mixture and stir it in until smooth. Spread the mixture over the shortbread crust and smooth it with a spatula.
Bake until the topping is golden and set, about 25 minutes. Cool in the pan on a wire rack and cut into 24 squares.