Instructions

for the dough

Grate 2 tablespoons butter on large holes of box grater and place in freezer. Cut remaining 8 tablespoons butter into ½-inch cubes.
Pulse ¾ cup flour, 1½ tablespoon minced fresh sage or thyme, sugar, and salt in food processor until combine, 2 pulses. Add cubed butter and process until homogeneous paste forms, about 30 seconds. Using your hands, carefully break paste into 2-inch chunks and redistribute evenly around processor blade. Add remaining ½ cup flour and pulse until mixture is broken into pieces no larger than 1 inch (most pieces will be much smaller), 4 to 5 pulses. Transfer mixture to bowl. Add grated butter and toss until butter pieces are separated and coated with flour.
Sprinkle 2 tablespoons ice water over mixture. Toss with rubber spatula until mixture is evenly moistened. Sprinkle remaining 2 tablespoons ice water over mixture and toss to combine. Press dough with spatula until dough sticks together. Transfer dough to sheet of plastic wrap. Draw edges of plastic over dough and press firmly on sides and top to form compact, fissure-free mass. Wrap in plastic and form into 5-inch disk. Refrigerate dough for at least 2 hours or up to 2 days. Let chilled dough sit on counter to soften slightly, about 10 minutes, before rolling. (Wrapped dough can be frozen for up to 1 month. If frozen, let dough thaw completely on counter before rolling.)

for the filling

Roll dough into 12-inch circle on floured counter. Loosely roll dough around rolling pin and gently unroll it onto 9-inch pie plate, letting excess dough hang over edge. Ease dough into plate by gently lifting edge of dough with your hand while pressing into plate bottom with your other hand.
Trim overhang to ½ inch beyond lip of plate. Tuck overhang under itself; folded edge should be flush with edge of plate. Crimp dough evenly around edge of plate. Wrap dough-lined plate loosely in plastic wrap and refrigerate until firm, about 30 minutes. Adjust oven rack to middle position and heat oven to 350 degrees.
Melt butter and sage into 8-inch skillet over medium-high heat. Continue to cook, swirling skillet occasionally, until butter is dark golden brown and has nutty aroma, about 2 minutes; set aside. Microwave squash in covered bowl until very soft and easily pierced with fork, 15 to 18 minutes, stirring halfway through microwaving. Carefully uncover, allowing steam to escape away from you, then drain squash; transfer to food processor. Add browned butter, salt, ginger, and nutmeg and process until smooth, about 1 minute, scraping down sides of bowl as needed. Transfer to large saucepan and set aside.
Line chilled pie shell with double layer of aluminum foil, covering edges to prevent burning, and fill with pie weights. Bake on foil-lined rimmed baking sheet until edges are set and just beginning to turn golden, 25 to 30 minutes, rotating sheet halfway through baking. Remove foil and weights, rotate sheet, and continue to bake crust until golden brown and crisp, 10 to 15 minutes longer. Transfer to wire rack. (Crust must still be warm when filling is added.)
Meanwhile, cook squash mixture and sugar in saucepan over medium heat until thick, shiny, and reduced to 2½ cups, 10 to 15 minutes, stirring constantly. Return squash mixture to now-empty processor bowl, add cream, milk, eggs and yolks, and vanilla, and process until well combined and smooth, about 15 seconds. Transfer filling to warm crust. Reduce oven temperature to 300 degrees and bake until edges of pie are set but center jiggles slightly and registers 160 degrees, 25 to 35 minutes. Let pie cool completely on wire rack, about 4 hours. Serve.