To make the crust, in the bowl of a food processor, pulse 2½ cups flour, sugar, and salt. Add butter and pulse until coarse, pea-sized crumbs appear, about 10 seconds. With the machine running, add vinegar and ¼ cup ice water and process until the dough just holds together, about 30 seconds. Squeeze a small amount of dough between your fingers and if it is very crumbly, add more ice water, 1 tablespoon at a time (2 tablespoons maximum). Do not overprocess.

Alternatively, if you don’t have a food processor, whisk together 2½ cups flour, sugar, and salt in a medium bowl. Toss the cubes of butter in the flour, coating each one. Then use your fingertips to press and flatten each cube, incorporating the fat into the flour. Work quickly as the butter must remain cold for best results. Add the vinegar and ¼ cup ice water and use a spatula to incorporate the liquid into the dough until a shaggy mass forms. Squeeze a small amount of dough between your fingers and if it is very crumbly, add more ice water, 1 tablespoon at a time (2 tablespoons maximum). Do not overmix.

Turn dough out onto a lightly floured surface and push together into a rough ball. Knead a few times to combine. Flatten into a rectangular shape (about 8x12”) with smooth edges (no cracks), cover with plastic wrap, and refrigerate at least 1 hour (or up to 3 days).

On a lightly floured surface, roll out dough into a rectangle about 13x17”. Roll the dough loosely around the rolling pin, and then unfurl it into the Baking Slab. Gently lift and settle the dough into the pan.

Trim the excess dough using kitchen shears, leaving a 1-inch overhang. Cut v-shaped notches of dough out of corners so they are not too thick and fold the excess dough over itself and into the sides of the Baking Slab. Press with your finger or a chopstick in regular intervals to crimp the dough into the sides of the Slab. Transfer to the refrigerator to chill 15 minutes while you make the filling.

Preheat the oven to 425F with racks on the middle and bottom rungs. Place a Sheet Pan on the bottom rack to preheat.

To make the filling, set aside 2 Tbsp. cane syrup in a medium bowl. Add 1 ½-2 cups of the nicest looking pecans (for the topping) and ¼ tsp. salt and toss to combine. Melt butter in Butter Warmer over medium heat, set aside to cool. Add sugar, remaining syrup, remaining 1 tsp. salt, vanilla, bourbon (if using), and cocoa to a medium bowl and whisk until incorporated. Add eggs and whisk until smooth. Add butter and whisk. Roughly chop remaining pecans and add to bowl, folding them in with a rubber spatula.

Fill the dough-lined Baking Slab with the pecan filling (do not overfill). Evenly sprinkle the syrup-glazed whole pecans over the pie, allowing them to settle on top of the filling.

Place Baking Slab on the preheated Sheet Pan and bake until the crust begins to turn golden, 15–20 minutes. Rotate Sheet Pan, move to center rack, and reduce heat to 375F. Continue baking until the filling is barely jiggly in the center and slightly puffed and crust is golden brown, 20-30 minutes more. Cool on a rack for at least 2 hours to let set before slicing.

Slice pie and serve with a dollop of whipped cream or scoop of ice cream.