Make the crust: Pulse the flour, granulated sugar and salt in a food processor to combine. Add half of the butter and pulse until combined. Add the remaining butter; pulse until the mixture looks like coarse meal with pea-size bits of butter. Add 5 tablespoons ice water; pulse a few more times until the dough just holds together when pinched (add up to 1 more tablespoon ice water if needed). Turn the dough out onto a piece of plastic wrap and gather together using the plastic wrap. Transfer about one-sixth of the dough to another piece of plastic wrap and pat into a disk. Pat the remaining dough into a larger disk; wrap both in plastic wrap. Refrigerate until firm, at least 1 hour and up to 24 hours.
Preheat the oven to 350 degrees F. Roll out the larger disk of dough into a 12-inch round (about ¿ inch thick) on a lightly floured surface. Ease the dough into a 9-inch pie plate; fold the overhanging dough under itself and crimp the edge with your fingers. Refrigerate until firm, 15 to 30 minutes. Roll out the smaller disk of dough until about 1/4 inch thick; cut out shapes using 2-inch cookie cutters. Place the cutouts on a small parchment-lined baking sheet and refrigerate until firm, 15 to 30 minutes.
Line the crust with foil and fill with dried beans or pie weights. Bake until the edge is lightly golden, about 20 minutes; remove the foil and beans and continue baking until the crust is dry and golden on the bottom, about 15 more minutes. Meanwhile, brush the cutouts with water and sprinkle with sanding sugar; bake until golden, about 15 minutes. Let the crust and cutouts cool completely.
While the crust cools, make the filling: Prick the sweet potatoes all over with a fork. Bake until very soft, 45 minutes to 1 hour. Let cool slightly, then peel and puree the flesh in a food processor until smooth. Transfer to a medium bowl; add the half-and-half, granulated sugar, eggs, brandy, vanilla, cinnamon and salt and whisk until smooth. Pour into the cooled crust.
Bake until the filling just starts setting, 30 to 35 minutes. Arrange the cutouts on the pie and continue baking until the crust is golden brown and the filling is set and puffed in the center, about 30 more minutes. Transfer to a rack and let cool completely, about 4 hours.