In small bowl, beat Bourbon-Pecan Mixture ingredients with whisk. Cover and refrigerate at least 8 hours but no longer than 2 days.
Heat oven to 350°F. On ungreased or silicone baking mat-lined cookie sheet, unroll crescent dough, and separate widthwise into 2 squares. Firmly press perforations to create 2 seamless squares.
Cut Brie in half lengthwise to create 2 equal-size rounds. Place 1 Brie half rind-side down on top of center of 1 dough square; cut out corners of dough square with cookie or canapé cutter (or just cut off corners diagonally). Set cutouts aside.
Spoon bourbon-pecan mixture evenly on top of Brie, then top with remaining Brie round, rind-side up. Place remaining dough square on top, and press dough evenly around Brie. Fold and roll bottom edges of dough over top edges; press to seal. Beat egg with 1 teaspoon bourbon whiskey, and brush evenly over dough.
Bake 20 to 25 minutes or until dough is golden brown and baked through. Cool 10 minutes before serving.