Grind the nuts with 1/2 cup flour in a food processor. Pulse on and off till the nuts are ground to a fine crumb. Add the rest of the flour and the cornstarch. Pulse to mix.
Step 2
In a separate bowl, cream the butter or margarine. Mix in the confectioners' sugar, vanilla, and bourbon. Work in the flour mixture. Knead the dough until smooth.
Step 3
Lightly spray your shortbread pan, or an 8 inch round pan, with a vegetable oil spray. Firmly press the dough into the pan, working from the center out. Poke the shortbread all over with a fork.
Step 4
Bake at 325 degrees F (165 degrees C) for 35 minutes, or till lightly browned. Let cool for 10 minutes in the pan. Loosen the edges with a knife, and flip the pan over onto a cutting board. Tap lightly to loosen from pan. Cut into serving pieces while still warm.
