INSTRUCTIONS
[Make the crust]
1. Pulse pecans, granulated sugar, and salt in a food processor until finely ground. Add 4 ½ cups flour and pulse until combined. Add butter and pulse until pea-size pieces remain. With motor running, stream in ¾ cup ice water; pulse until dough begins to form large clumps.
2. Turn out dough onto a work surface. Knead briefly to combine, then pat into a flat rectangle. Wrap dough in plastic wrap and chill 1 hour.
3. Arrange a rack in center of oven; preheat to 375°F. Line baking sheet with parchment paper, leaving an overhang on 2 long sides.
4. Transfer dough to a lightly floured, long piece of parchment (at least 20") and roll out to a larger rectangle. Top with another floured piece of parchment; roll to a 19x15" rectangle about 1/4" thick (if dough becomes too warm, chill 5 minutes). Remove top layer of parchment. Gently transfer parchment-lined dough to baking sheet so short sides of parchment hang over short sides of baking sheet. Press dough up sides of baking sheet until dough is just hanging over rim, then trim so edges are flush. Crimp with a fork, if desired, then prick bottom of dough with fork. Freeze dough 20 minutes.
5. Bake crust until edges are lightly browned and beginning to set, 15-20 minutes. Transfer baking sheet to a wire rack and let cool.
[Make the filling]
6. Melt butter in a large saucepan over medium heat. Cook, stirring occasionally, until solids begin to brown and butter smells nutty, about 5-8 minutes. Remove from heat and immediately stir in granulated sugar. Add corn syrup, molasses, lemon juice, vanilla, and salt and stir to combine. Add eggs and whisk until smooth.
7. Pull out center rack of oven; place crust on rack. Pour filling into crust and carefully return rack to oven. Bake pie 10 minutes. Reduce oven temperature to 325°F and continue to bake until filling is set but wobbles slightly when baking sheet is tapped, 20-25 minutes more. Transfer pan to a wire rack and let cool.
[Make the candied pecans]
8. Increase oven temperature to 350°F. Whisk egg white in a large bowl until frothy. Add brown sugar and salt and whisk to combine. Add pecans and mix with a spoon until evenly coated.
9. Spread pecan mixture on a foil-lined rimmed baking sheet and bake, tossing once halfway through, until toasted and crisp, about 8 minutes. Toss pecans, then transfer to a large bowl. Sprinkle with granulated sugar and toss to coat. Let cool, tossing occasionally to ensure pecans don't stick together, then coarsely chop.
[Make the chocolate ganache and finish the pie]
10. Place chocolate in a small bowl. Bring cream to a simmer in a small saucepan, then pour over chocolate. Tap bowl to submerge chocolate in cream; let stand 1 minute.
11. Using a small whisk, stir chocolate mixture in the center until shiny and smooth. Pour ganache over pie and spread evenly with an offset spatula. Sprinkle candied pecans over pie while chocolate is warm. Let pie cool at room temperature at least 2 hours or chill 1 hour.
12. Using parchment, transfer tart to a large cutting board or serving platter. Cut into squares to serve.
[Do Ahead]
13. Pie can be made 1 day ahead; loosely cover and chill.
