Espresso-Flavored Dark Chocolate Cheesecake
1/2 cup brewed coffee
2 tablespoons unsalted butter
6 ounces semisweet or bittersweet chocolate, coarsely chopped
1 tablespoon vanilla extract
1 tablespoon brandy
2 teaspoons instant espresso powder
12 ounces cream cheese
1/2 cup granulated sugar
1/3 cup light brown sugar
1 cup mascarpone cheese (about 12 ounces)
2 large eggs
4 large egg yolks
Whipped mascarpone cream:
1/2 cup (about 4 ounces) mascarpone cheese
1 cup heavy cream
Confectioners' sugar for dusting
9 chocolate-covered espresso beans (optional)
Make the crust: Line two baking sheets with parchment paper. On a work surface lightly dusted with flour, carefully unfold one of the thawed sheets of puff pastry dough. Lightly dust the top of the dough with flour. Using a floured rolling pin, roll out the dough into a 10-inch square. Transfer the dough to one of the prepared baking sheets. Repeat the rolling process for the second sheet of dough. Refrigerate until the dough is very firm, at least two hours. If two ovens are available, position a rack in the center of each oven and preheat to 375 degrees(F). Otherwise, use one oven and bake each sheet of dough separately. Have ready two more baking sheets of equal size to those holding the dough. Prick the pieces of dough very well on both sides with the tines of a fork and return them to their prepared baking sheets; refrigerate until firm, if necessary.
Remove one of the pans of dough from the refrigerator and place the dough on a lightly floured work surface. Using a pastry wheel or a sharp paring knife, trim the dough into nine 3-inch squares. Place the small squares on the prepared baking sheet; refrigerate until firm, if necessary. Before baking, cover each sheet of dough with a piece of parchment and place another baking sheet over the parchment-covered dough. Bake the dough for 20 to 25 minutes or until the pastry is golden brown and baked through. The smaller squares will take less time than the large square. During the baking process, invert the double-pan assembly at least once to make sure that the pastry bakes evenly. Allow the baked puff pastry, sandwiched between the pans, to cool completely on a wire rack.
Make the filling: Reduce the oven heat to 325 degrees(F). Lightly butter the sides and bottom of the 9-inch square baking pan. Line the bottom with a square of parchment paper. With a sharp serrated knife, trim the large square of baked puff pastry to fit the baking pan and place the trimmed square in the bottom of the prepared pan. Combine the coffee, butter and chopped chocolate in the top of a double boiler over hot, not simmering, water. Stir the mixture until the chocolate and butter are completely melted and the mixture is smooth. Remove the top part of the double boiler from the bottom. Whisk the vanilla extract, brandy and espresso powder into the warm chocolate mixture to make a smooth blend; set aside to cool until tepid.
In the 4 1/2 -quart bowl of a heavy-duty electric mixer, using the paddle attachment, beat the cream cheese on medium- low speed, until creamy and totally free of lumps, about two minutes. Scrape down the inside of the bowl and paddle, as needed. Gradually add the granulated and brown sugars and beat until combined. Mix in the chocolate mixture and the mascarpone cheese. On low speed, beat in the eggs And yolks, one at a time, making sure that each is combined before adding the next, but being careful not to overbeat and incorporate air. Pour the filling onto the crust. Put the baking pan in a larger roasting pan. Put the roasting pan in the oven and fill with enough hot water to come half-way up the sides of the baking pan. Bake until the top of the cake is set, about 40 minutes. Remove the baking pan from the water bath. Immediately run the tip of a thin-bladed paring knife between the edge of the cake and the pan. (This step will reduce the chances of the top of the cheesecake cracking as it cools). Place the cheesecake on a wire rack and allow to cool completely. Cover the top of the pan tightly with plastic wrap and refrigerate for at least 4 hours or overnight, until cold.
Cover a baking sheet or a 10-inch cardboard square with plastic wrap. Run a thin, flexible knife between the cake and the sides of the pan to loosen. Place the baking sheet or cardboard square on top of the cheesecake and invert. (If the cheesecake does not release, briefly place the cake pan on a burner, over very low heat, for a few seconds and invert again). Remove the parchment from the bottom of the cheesecake.
Make the whipped mascarpone cream: In a chilled medium-size bowl, mix the mascarpone cheese and heavy cream until well-blended. Using a hand-held mixer set at medium speed, whip the mascarpone-cream mixture until soft peaks form; do not over-whip as the mascarpone cheese may curdle. Refrigerate until needed.
Assemble the cheesecake: Spread about 1/2 cup of the whipped mascarpone cream over the top of the cheesecake. Fill a pastry bag fitted with a medium closed star tip (such as Ateco #6) with the remainder of the whipped mixture.
Arrange the nine small puff pastry squares over the cream layer and lightly dust the squares with confectioners' sugar. Pipe out rosettes of the whipped cream mixture in the center of each square. If desired, place a chocolate-covered coffee bean in the center of each rosette. Refrigerate the assembled cheesecake for up to 3 hours. Remove the cheesecake about 15 minutes before serving. To serve, cut the cheesecake into the delineated squares, with a sharp thin-bladed knife, dipping the blade in hot water and wiping it dry after each slice.