Start by making the crust so it has time to chill before rolling. Add the all-purpose flour, salt, and granulated sugar to a food processor and pulse briefly to combine the dry ingredients evenly. Scatter the cold butter cubes and cold vegetable shortening over the flour mixture and pulse in short bursts around 10 to 12 times, just until the fat pieces are reduced to about the size of small peas and the mixture looks like coarse crumbs; avoid overmixing because you want visible bits of fat for flakiness.​

With the processor running, drizzle in the ice water through the feed tube, starting with 3 tablespoons and adding more a spoonful at a time until the dough just begins to clump and holds together when pinched between your fingers. As soon as the dough can be pressed into a cohesive mass, stop adding water so the crust does not become tough, then turn the mixture out onto a lightly floured work surface.​

On the counter, gently gather the crumbs together with your hands and press them into a ball without kneading or overworking, which would develop gluten and make the crust dense. Once the dough forms a rough ball, flatten it into a disk about 1 inch thick, which makes it easier to roll later, and wrap it tightly in plastic wrap. Transfer the wrapped dough to the refrigerator and chill it for at least 30 minutes, or up to a couple of hours, so the fat firms up and the flour hydrates for better texture.​

While the dough chills, prepare your pie dish by lightly greasing it if desired, and clear a space on your counter for rolling. When the dough has rested, dust your work surface and rolling pin with flour, then place the disk in the center and start rolling from the middle outward, turning the dough a quarter turn after each few passes to keep it even and prevent sticking.​

Roll the dough into a circle roughly 12 inches across, about 3 to 4 mm thick, large enough to fit a standard 9-inch pie dish with some overhang. To move it without tearing, loosely roll the dough around the rolling pin or fold it gently into quarters, then lift and unroll or unfold it over the pie dish so it drapes evenly. Ease the dough into the corners of the dish by lifting the edges slightly and letting it settle rather than stretching it, which can cause shrinking in the oven.​

Trim the overhanging dough to about 1 inch beyond the rim, then tuck that extra dough under itself along the edge to create a thicker border that will hold a crimp. Use your fingers or a fork to crimp the edge all the way around, making a decorative pattern that also helps seal the crust. Place the lined pie shell back in the refrigerator to chill while you prepare the filling and preheat your oven, helping the crust keep its shape when it bakes.​

Preheat your oven to 425°F (220°C) so it is fully heated by the time the pie goes in. In a large mixing bowl, combine the pumpkin puree, evaporated milk, eggs, granulated sugar, and pumpkin pie spice. Whisk the mixture steadily until it looks smooth and uniform, with no streaks of egg or clumps of spice; this creates a silky custard that bakes evenly.​

If you see any small lumps, you can switch to a hand mixer on low or pour the filling through a fine mesh sieve into a clean bowl for an extra-smooth texture. Let the filling sit for a couple of minutes so any large air bubbles can rise to the surface, then give it a gentle stir to redistribute everything. Keep the filling at room temperature rather than chilling it, because a big temperature contrast between filling and oven can affect how the custard sets.​

Set the chilled pie shell on a baking sheet, which makes it easier to move in and out of the oven and catches any drips. Carefully pour the pumpkin filling into the crust, filling it until the mixture comes close to the top but still leaves a small gap so it does not overflow as it puffs slightly in the oven. Tap the baking sheet lightly on the counter to release any trapped air bubbles that might create cracks later.​

Place the pie on the center rack of the preheated oven and bake at 425°F (220°C) for 15 minutes to set the crust and give the custard a head start. After this initial high-heat phase, reduce the oven temperature to 350°F (175°C) without removing the pie, and continue baking for about 50 to 55 minutes until the filling is mostly set. The edges should look puffed and dry, while the very center should still jiggle slightly like soft gelatin when you gently nudge the pan, which means the custard will finish setting as it cools.​

Once the pie reaches this stage, take it out of the oven and place it on a wire rack so air can circulate around the pan and cool it evenly. Allow the pie to cool at room temperature for about 30 minutes; during this time, the residual heat continues to cook the center gently, helping prevent cracks. After that initial cooling, move the pie to the refrigerator and chill it for at least a couple of hours, or until fully cold, which helps the filling firm up and makes slicing much easier.​

Keep the pie loosely covered in the fridge to protect it from absorbing other odors while avoiding condensation dripping onto the surface. When ready to serve, use a sharp, thin knife to cut neat wedges, wiping the blade between slices for the cleanest presentation. Pumpkin pie is delicious on its own or with a dollop of softly whipped cream and a light sprinkle of extra pumpkin pie spice or grated nutmeg on top.