White Chocolate and Summer Berry Napoleons - white chocolate

Method

• Stir white chocolate in large bowl set over saucepan of barely simmering water until melted and smooth.
• Remove from heat.
• Bring milk to simmer in heavy medium saucepan.
• Whisk milk barely simmering water until melted and smooth.
• Remove chocolate from heat.
• Bring milk to simmer in heavy medium saucepan.
• Whisk milk into chocolate.
• Let chocolate mixture cool until just beginning to thicken, stirring occasionally, about 1 hour.
• Using electric mixer, beat cream and vanilla in another large bowl until medium-firm peaks form.
• Fold whipped cream into chocolate mixture in 3 additions.
• Cover and refrigerate.
• Preheat oven to 400F.
• Line 17x11x1-inch baking sheet with parchment paper.
• Roll out 1 pastry sheet on lightly floured surface to 15x12-inch rectangle.
• Cut crosswise into three 12x5-inch rectangles.
• Repeat rolling and cutting with remaining pastry sheet to make six 12x5-inch pastry rectangles total.
• Transfer 2 pastry rectangles to prepared baking sheet, spacing evenly.
• Cover remaining pastry rectangles and chill.
• Pierce pastry rectangles on baking sheet all over with fork.
• Top with second piece of parchment.
• Place another 17x11x1-inch baking sheet atop parchment to weigh down pastry rectangles as they cook.
• Bake pastries until edges and bottoms are golden, about 10 minutes.
• Remove baking sheet and parchment paper from atop pastries.
• Turn pastries over.
• Continue baking uncovered until bottoms are golden, about 5 minutes longer.
• Transfer pastries to rack; cool.
• Repeat piercing and baking with remaining 4 pastry rectangles in 2 more batches.
• (White chocolate cream and pad pastry rectangles can be prepared 1 day ahead.
• Keep cream refrigerated.
• Store pastry rectangles airtight at room temperature.)
• Place 1 pastry rectangle on work surface.
• Spread 1 1/2 cups of chocolate cream over pastry.
• Gently toss all berries in large bowl.
• Arrange of berries in single layer over chocolate cream.
• Place second pastry rectangle atop berries.
• Spread 1 cups of chocolate cream atop second pastry rectangle.
• Top with of berries.
• Top with third pastry rectangle.
• Repeat with remaining 3 pastry rectangles, chocolate cream and berries to form second napoleon.
• (Can be made 4 hours ahead.
• Refrigerate.)
• Using serrated knife, cut each pastry crosswise into 10 equal pieces.
• Sprinkle powdered sugar over each and serve.