Make the crust: Pulse the flour, cocoa powder, granulated sugar and salt in a food processor to combine. Add the shortening and pulse until the mixture looks like cornmeal. Add the butter and pulse a few times until it is in pea-size pieces. Add the ice water and vodka and pulse until the dough starts coming together but is still crumbly. Turn out onto a piece of plastic wrap and pat into a disk, using the plastic wrap to help you. Wrap and refrigerate until very firm, at least 1 hour and up to 24 hours.
Preheat the oven to 350 degrees F. Roll out the dough into a 12-inch round on a lightly floured surface. Ease into a 9-inch pie plate. Fold the overhanging dough under itself and crimp the edge with your fingers. Refrigerate until firm, at least 30 minutes. Line the crust with foil and fill with dried beans or pie weights. Bake until the edge is dry, about 20 minutes. Remove the foil and beans and continue baking until dry all over, 15 to 20 more minutes. Transfer to a rack and let cool completely.
Meanwhile, make the filling. Put the chocolate in a medium heatproof bowl. Combine 3/4 cup heavy cream and the butter in a small saucepan; bring to a boil, then immediately pour over the chocolate. Add the vanilla and salt (do not stir), cover with plastic wrap and let stand 5 minutes. Whisk until melted and smooth. (If there are pieces of unmelted chocolate, microwave in 15-second intervals until smooth.) Set aside to cool.
Beat the remaining 1 3/4 cups heavy cream and the confectioners' sugar in a large bowl with a mixer on medium speed until stiff peaks form, about 4 minutes. Gently fold the whipped cream into the chocolate mixture in three batches (do not overmix; the filling should be light and airy). Transfer to the cooled pie crust and smooth the top. Cover loosely with plastic wrap and refrigerate until firm, at least 2 hours.
Remove the pie from the refrigerator 15 minutes before serving. Make the topping: Beat the heavy cream and confectioners' sugar in a large bowl with a mixer on medium speed until soft peaks form, about 3 minutes. Stir the chocolate syrup and espresso powder in a small bowl until dissolved. Fold about 2 tablespoons of the chocolate syrup mixture into the whipped cream, then spread on the pie. Drizzle with the remaining syrup mixture; sprinkle with the espresso beans.