How to Make It
In a bowl of a standing mixer fitted with the paddle, beat the butter until creamy. Add the 1 1/4 cups of flour and the confectioners' sugar, salt and vanilla seeds and beat at low speed until smooth. Beat in the egg white. Scrape the dough onto a sheet of plastic wrap; press into a 6-inch disk. Wrap up and freeze until firm, at least 20 minutes.
Preheat the oven to 350°. On a well-floured work surface, roll the dough out to a 12-inch round. Ease the dough into an 11-inch fluted tart pan with a removable bottom; press it into the pan. Trim the overhanging dough and use it to patch any tears or holes. Freeze the tart shell just until firm, 10 minutes.
Line the dough with parchment paper and pie weights and bake for 20 minutes, until nearly set. Remove the weights and paper and bake for 20 minutes, until golden.
Spread the pecans on a baking sheet and toast for 10 minutes, until fragrant. Let cool, then chop the nuts. In a bowl, whisk the corn syrup, brown sugar, cream, eggs, bourbon, vanilla and salt. Stir in the butter and pecans.
Set the tart pan on the baking sheet and set it in the oven. Scrape the filling into the tart shell and bake for about 35 minutes, until the custard is set and puffed; cover the edge with strips of foil if it's browning too fast. Transfer to a rack to cool, then remove the ring and slide the tart onto a serving plate.
In a bowl, using an electric mixer, beat the cream with the confectioners' sugar and bourbon until soft peaks form. Cut the tart into wedges and serve with the whipped cream.