If you like cannoli, you're going to love this dazzling cake inspired by the beloved Sicilian confection. The creamy ricotta filling is sandwiched between crisp, flaky layers of something you might already have in your freezer: puff pastry.
Preheat oven to 400 degrees with rack in center. Place two rounds of puff pastry on a parchment-lined rimmed baking sheet. Position a wire rack, upside-down and diagonally, on rim of baking sheet. Bake 10 minutes. Reduce oven temperature to 375 degrees and bake 20 minutes more. Remove from oven and carefully remove rack. Switch oven to broiler setting. Dust rounds liberally with confectioners' sugar and return to oven, with rack in lower third. Broil, rotating rounds halfway through, until sugar is completely melted and caramelized (but not burned), about 3 minutes. Carefully transfer rounds to a wire rack; let cool completely. Repeat process with remaining round of puff pastry.
In a medium bowl, stir together ricotta, confectioners' sugar, vanilla, cinnamon, and salt until well combined and smooth. Stir in chopped chocolate and orange peel. Gently fold in whipped cream. Refrigerate in an airtight container at least 2 hours and up to 2 days.
Place pistachios on a large plate. Using a pastry brush, paint edges of each pastry round with melted chocolate, then roll in pistachios to coat. Refrigerate until set, about 20 minutes.
Place one pastry round on an 8-inch cardboard cake round; using an offset spatula, spread 1 1/2 cups filling evenly over top. Repeat with second pastry round and remaining filling. Top with remaining pastry round. Refrigerate until set, about 30 minutes; serve.