1 tablespoon sugar
1½ teaspoons kosher salt
2 cups all-purpose flour, plus more for surface
5 tablespoons chilled unsalted butter, cut into pieces
3 tablespoons vegetable shortening
1 tablespoon apple cider vinegar
FILLING AND ASSEMBLY
2 cups pecan halves
4 large eggs, room temperature, beaten to blend
1 cup light corn syrup
⅔ cup (packed) light brown sugar
1 tablespoon robust-flavored (dark) molasses (not blackstrap)
1 tablespoon vanilla extract
1 teaspoon kosher salt
6 tablespoons unsalted butter, melted, slightly cooled
Vanilla ice cream (for serving)
Pulse sugar, salt, and 2 cups flour in a food processor until combined. Add butter and lard and pulse until mixture resembles coarse meal with a few pieces of butter and lard visible, about fifteen 1-second pulses. With motor running, drizzle in vinegar and 5½ Tbsp. ice water and pulse until dough is still crumbly but just holds together when squeezed (add 1 tsp. water at a time if necessary, but be careful not to overwork dough).
Turn out dough onto a work surface. Knead 1–2 times, pressing just to incorporate any shaggy pieces. Flatten into a 6"-wide disk. Wrap with plastic wrap and chill at least 1 hour.
Preheat oven to 425°. Roll out dough on a lightly floured work surface to a 14" round. Transfer to a 9" pie dish. Pick up edges and allow dough to slump down into dish, letting excess dough hang over dish. Trim, leaving about a 1" overhang. Fold overhang under; pinch and crimp. Chill 30 minutes.
Line dough with parchment paper or foil, leaving some overhang. Fill with pie weights or dried beans. Bake until crust is dry around the edges and just beginning to lightly brown, 25–35 minutes. Carefully remove parchment and weights and reduce oven temperature to 350°. Bake until crust is set and beginning to brown in the center, 10–15 minutes. Transfer to a wire rack and let cool.
Do Ahead: Dough can be made 3 days ahead; keep chilled, or freeze up to 2 months. Crust can be baked 1 day ahead; tightly wrap and store at room temperature.
FILLING AND ASSEMBLY
Preheat oven to 350°. Toast pecans on a rimmed baking sheet until browned and fragrant, 8–10 minutes. Let cool.
Reduce oven temperature to 325°. Whisk eggs, corn syrup, brown sugar, molasses, vanilla, and salt in a large bowl until smooth. Slowly whisk in melted butter until combined. Fold in pecans and pour into cooled crust.
Bake pie until edges are set and slightly puffed but center is recessed and wobbles like Jell-O, 55–70 minutes (it will continue to set after baking). Transfer to a wire rack and let cool at least 3 hours before slicing. Serve with ice cream.