Instructions

for the crust

Combine water and sour cream in bowl. Process flour, sugar, and salt in food processor until combined, about 5 seconds. Scatter butter over top and pulse until butter is size of large peas, about 10 pulses. Add sour cream mixture and pulse until dough forms clumps and no dry flour remains, about 12 pulses, scraping down sides of bowl as needed.
Turn dough onto sheet of plastic wrap and form into 4-inch disk. Wrap tightly in plastic and refrigerate for 1 hour. (Wrapped dough can be refrigerated for up to 2 days or frozen for up to 1 month. If frozen, let dough thaw completely on counter before rolling.)
Let chilled dough sit on counter to soften slightly, about 10 minutes, before rolling. Roll dough into 12-inch circle on lightly floured counter. Loosely roll dough around rolling pin and gently unroll it onto 9-inch pie plate, letting excess dough hang over edge. Ease dough into plate by gently lifting edge of dough with your hand while pressing into plate bottom with your other hand.
Trim overhang to ½ inch beyond lip of plate. Tuck overhang under itself; folded edge should be flush with edge of plate. Crimp dough evenly around edge of plate using your fingers. Wrap dough-lined plate loosely in plastic and refrigerate until dough is firm, at least 30 minutes. Adjust oven rack to lower-middle position and heat oven to 400 degrees.
Line chilled pie shell with aluminum foil and, while pressing into plate bottom with 1 hand to keep foil flush with bottom of plate, work foil around crimped edge with your other hand. Fill foil-lined dough to lip of plate with pie weights. Bake until edges are dry and pale, about 30 minutes. Remove foil and pie weights and continue to bake until bottom begins to color, about 10 minutes longer. Transfer to wire rack. Lower oven temperature to 325 degrees.

for the filling

Melt butter and chocolate in bowl at 50 percent power, stirring halfway through microwaving, until melted, about 2 minutes. Add corn syrup, sugar, eggs, vanilla, and salt to chocolate mixture and whisk until combined. Stir in pecans.
Place pie shell on rimmed baking sheet (shell needn't be completely cool before proceeding). Pour filling into shell and distribute evenly with rubber spatula. Bake until pecan layer that forms on top begins to crack and filling in center of pie registers 185 to 190 degrees (filling will jiggle slightly when pie is shaken), 1 hour to 1 hour 5 minutes, rotating sheet halfway through baking. Let pie cool on wire rack until set, at least 4 hours.

for the whipped cream

Using stand mixer fitted with whisk attachment, whip cream, sugar, 1 tablespoon bourbon, vanilla, and salt on medium-low speed until foamy, about 1 minute. Increase speed to high and whip until soft peaks form, 1 to 3 minutes. Add remaining 1 tablespoon bourbon to taste. (Whipped cream can be refrigerated in airtight container for up to 24 hours.)
Serve pie with whipped cream.

to make ahead

At end of step 7, pie can be wrapped tightly in plastic wrap, then in aluminum foil, and frozen for up to 1 week. To serve, unwrap pie completely and let thaw at room temperature for 5 hours. Make whipped cream while pie thaws.