In the bowl of a standing mixer, paddle attachment, combine the flour, sugar and salt. Add the shortening and cold butter and mis until the mixture resembles coarse crumbs. Slowly add the cold water while mixing on medium speed just until the dough comes together, then immediately stop mixing. Wrap the dough in plastic wrap and refrigerate until ready to use.
Place the corn syrup, sugar bourbon and vanilla in the bowl of a stand mixer with paddle attachment. Mix at low speed for 2 minutes. Add the melted butter and slowly incorporate. Add one egg at the time and mix for 2 minutes in between adding eggs to the mixture. Mix until the filling is well incorporated.
Preheat the oven to 350F.
Remove the dough from the refrigerator and roll out on a lightly floured surface with a rolling pin to ¼ inch thick. Line an un-greased 9-inch pie pan with the dough. Place the pecan pieces on the bottom of the pie shell. Pour the filling into the crust covering all the pecan pieces. Place a dough protector ring around the dish to not burn the crust. Bake in the center rack for 1 hour and 15 minutes. Remove from the oven and let cool completely before slicing.