Make the Crust: Process ¾ cups of the flour, the sugar and salt together in a food processor until combined, about 2 one-second pulses. Add the butter and shortening and process until a homogenous dough just starts to collect in uneven clumps, about 7 to 10 seconds (the dough will resemble cottage cheese curds with some very small pieces of butter remaining, but there should be no uncoated flour). Scrape down the sides and bottom of the bowl with a rubber spatula and redistribute the dough evenly around the bowl. Add the remaining ½ cup flour and pulse until the mixture is evenly distributed around the bowl and the mass of dough has been broken up, 4 to 6 quick pulses. Empty the mixture into a medium bowl.
Sprinkle the vodka and water over the mixture. With a rubber spatula, use a folding motion to mix, pressing down on the dough until it is slightly tacky and sticks together.
Roll out on a generously floured work surface to a 12-inch circle. Transfer to a 9-inch pie plate, leaving at least a 1-inch overhang on each side. Working around the circumference, ease the dough into the plate by gently lifting edge of the dough with one hand while pressing into the plate bottom with other hand. Dust off any excess flour with a pastry brush. With scissors or kitchen shears, trim the edge so that it overhangs by 1 inch. Fold the overhang under itself; the folded edge should be flush with edge of pie plate. Flute the dough or press the tines of a fork against dough to flatten it against the rim of pie plate. Wrap with plastic and refrigerate at least 2 hours and up to one day in advance.
Blind Bake the Crust: Adjust oven rack to lower-middle position and preheat oven to 350 degrees F. Line the chilled pie dough with aluminum foil, being sure to cover the edges of the crust, and use granulated sugar to fill the whole pie plate. Bake for 40 minutes; remove the foil and sugar and set the crust aside while you make the filling.
Make the Filling: In the bowl of an electric mixer on medium-high speed with a whisk attachment (or in a large bowl with a whisk and a lot of elbow grease), whip together the butter, sugars, corn syrup, eggs, bourbon and vanilla extract until frothy. Fold in the walnuts and chocolate chips with a rubber spatula.
Bake: Pour into the prepared pie crust (you may have more filling than will fit into your pie pan - just fill it up as far as you can). Place a pie shield over the edges of the pie crust. Bake for 50 to 60 minutes or until the pie looks set and yet soft, like gelatin, when gently pressed with the back of a spoon. Cool completely at room temperature (at least 4 hours) before slicing into the pie.
Notes
Pie Plate: I use and recommend this glass pie plate.
Pie Crust by Hand Instructions: In a large mixing bowl, whisk together the flour, sugar, and salt. Toss the butter and shortening with the flour mixture to break up any big pieces. Use a pastry blender to cut the butter and shortening into the flour mixture until it looks like coarse crumbs.
Nuts: While walnuts are traditional for derby pie, you can also substitute pecans. And if you have a nut allergy, substitute the same amount of traditional, old-fashioned rolled oats for the nuts.
Chocolate: The sky is the limit! Semisweet is my preference, but you can use dark, or milk chocolate, as well. While I like chocolate chips because they somewhat hold their shape, you could use chopped chocolate for a meltier texture.
Bourbon: Any type of bourbon or whiskey will work in this recipe, and you can omit it entirely if you'd like, too.
Filling: While my blind baking technique is failproof and keeps the crust from shrinking, if yours does shrink, you may not have enough space for all of the filling. Use as much as you can; you can always use dough scraps and extra filling for little mini pies in a mini muffin tin, sort of like my pecan tassies!
Make-Ahead: The pie can be baked up to one day in advance of serving.
Storing: The pie can be kept, loosely covered, in the refrigerator, for up to 4 days.
Freezing: Allow the pie to cool completely, then wrap tightly in plastic wrap and foil and freeze for up to 3 months. Thaw in the refrigerator overnight, then slice and serve.
Cookie Bars: Want something more portable or to serve a crowd? Bake up this pie filling using the crust and directions from my chunky pecan bars.