Warm Peach Shortcakes with Bourbon-Brown Sugar Cream

3 pounds fresh peaches, peeled#189; cup packed light brown sugar2 tablespoons fresh lemon juiceShortcakes2#189; cups unbleached, all-purpose flour7 tablespoons sugar, divided4 teaspoons baking powder#189; teaspoon salt1/4 teaspoon baking soda1/2 cup (1 stick) chilled, unsalted butter, cut into 1/2- inch pieces1/2 cup solid vegetable shortening, frozen, cut into 1/2 -inch pieces2/3 cup chilled buttermilk1 large egg1 large egg white3/4 cup finely chopped pecans Sauce1 cup chilled heavy whipping cream2 tablespoons (packed) light brown sugar11/2 tablespoons bourbonFor the peaches: Cut the peach slices in half. In a large bowl, gently toss peaches, brown sugar and fresh lemon juice; let stand at room temperature until juices form, about 2 hours, tossing occasionally.For the shortbread: Position rack in center of oven and heat to 425 degrees.Whisk flour, 6 tablespoons of the sugar, baking powder, salt, and baking soda in medium bowl to blend. Add butter and shortening and rub in with fingertips until coarse meal forms.Whisk together buttermilk and 1 egg in small bowl. Add to flour mixture and stir until moist clumps form. Gather dough together; turn out onto floured work surface and knead gently just until dough holds together, about 5 turns (dough will be moist). Pat dough into 9- by 6-inch rectangle; cut into 6, 3-inch squares. Transfer to heavy, ungreased baking sheet, spacing apart (see note).Whisk egg white in small bowl until foamy; stir in pecans and spread over biscuits. Sprinkle squares with remaining sugar. Bake biscuits until puffed and light golden, about 18 minutes. Cool biscuits 10 minutes.For the sauce: Beat cream, brown sugar and bourbon in medium bowl until soft peaks form.To serve: Cut warm biscuits horizontally in half with serrated knife. Place bottom halves on serving plates. Top with peaches. Spoon generous dollop of bourbon whipped cream atop each; cover with biscuit tops. Garnish each with dollop of bourbon whipped cream.Serves six.Cook's note: Shortbread dough can be prepared to this point up to 4 hours ahead. Cover tightly and refrigerate.