Make the crust. Whisk the flour, sugar and salt. Cut in the cold butter with a pastry blender. Mix the ice water and vinegar and add a little at a time, just until the dough holds together. Smear and fold briefly so streaks of butter remain. Divide into two disks, one slightly larger, wrap and chill at least 1 hour.

Line the pan. Roll the larger disk to about 19 by 14 inches and fit it into the jelly roll pan, letting the edges hang over. Chill while you make the filling.

Cook the filling. Melt the butter in a large, wide pot over medium heat. Stir in the cinnamon, nutmeg and salt, then add the apples and brown sugar and toss to coat. Cook, stirring, 4 to 6 minutes, until the apples just start to soften. Stir in the cornstarch slurry and cook 1 to 2 minutes, until the juices thicken and turn glossy. Remove from the heat, stir in the lemon zest and let cool completely, then spread evenly in the lined pan.

Top and seal. Roll the smaller disk to 15 by 10 inches and lay it over the filling. Fold the bottom overhang over the top crust and pinch to seal. Chill 15 minutes in the freezer or 30 minutes in the fridge.

Bake. Set a rack in the lower third of the oven and heat to 375°F, with a parchment-lined sheet on the rack below to catch drips. Cut vents in the top, brush with egg wash and sprinkle with turbinado sugar. Bake 40 to 55 minutes, until deep golden, the juices bubble through the vents and the apples are tender.

Cool. Cool completely on a rack before slicing.

Make the bourbon sauce. Melt the butter in a medium saucepan over medium heat and whisk in the brown sugar until smooth. Whisk in the cream and simmer 3 to 4 minutes, until slightly thickened. Off the heat, carefully whisk in the bourbon, vanilla and salt; it will bubble up. Return to low heat for 1 minute.

Serve. Slice the pie and spoon the warm bourbon sauce over the top. The sauce thickens as it cools.