In the bowl of a food processor fitted with the metal blade, process 1 1/2 cups flour, salt, and sugar until combined, about two 1-second pulses.

Add butter and shortening and process until dough just starts to collect in uneven clumps, about 10-15 seconds; there may be small pieces of butter left but there should be no uncoated flour. Scrape bowl with rubber spatula and redistribute dough evenly around processor blade. Add remaining cup of flour and pulse until mixture is evenly distributed around bowl and mass of dough has been broken up, 4 to 6 pulses. Transfer mixture into medium bowl.

Sprinkle vodka and water over mixture. Using a folding motion, use a rubber spatula to mix, pressing down on dough until dough is slightly tacky and sticks together. Divide dough into 2 even balls and flatten each into 4-inch disk. Wrap each in plastic wrap and refrigerate at least 45 minutes or up to 2 days. It may also be frozen and taken out and thawed in the fridge the day before you need it.