NAPOLEON

Steps:

• Make puff pastry strips: Lightly flour a clean work surface. Using a rolling pin, gently roll out dough into a 16-by-18-inch rectangle about 1/8 inch thick, being careful not to press too hard around the edges. Using a pastry wheel or sharp knife, cut rectangle crosswise into thirds, with each strip 6 by 16 inches. Transfer to a baking sheet; dock, or pierce, the dough all over with a fork. Cover with plastic wrap; place in refrigerator 1 hour.
• Preheat oven to 425 degrees. Transfer to oven; bake until strips are puffed and golden all over, about 14 minutes. Set a baking sheet directly on pastry strips, and continue baking until pastry is cooked through and well browned, about 6 minutes. Remove top baking sheet; bake 4 minutes more. Transfer to a wire rack to cool completely. Using a serrated knife, trim each to 4 1/4 by 12 inches.
• Make the glaze: In a small saucepan, bring heavy cream just to a boil. Place dark chocolate in a bowl, and pour hot cream over chocolate; whisk until chocolate is melted and mixture is combined. Whisk in corn syrup. Strain through a fine mesh sieve into a clean bowl.
• Place white chocolate in a medium heat-proof bowl set over a pan of simmering water. Whisk until chocolate is melted, and remove from heat. Let cool.
• Using an offset spatula, spread dark chocolate glaze over one side of the flattest puff pastry strip, making sure to coat entire surface. Place white chocolate in a piping cone; pipe thin lines 3/4 inch apart across width of chocolate-coated strip. To create the distinctive flourish, gently drag the tip of a paring knife or a skewer lengthwise through both coatings, in lines perpendicular to the white chocolate lines. Begin at one of the short ends, and make each line 3/4 inch apart. Alternate the direction each time.
• Place one of the unglazed puff pastry strips on a serving tray. Spread half the pastry cream over the top, leaving a 1/2-inch border all around. Top with remaining unglazed pastry strip; press down gently, and repeat with remaining pastry cream. Top with glazed pastry strip. Transfer to refrigerator, and chill 30 minutes uncovered. Using a long serrated knife, cut into six pieces, and serve.