Bon Appétit: White Chocolate Espresso Torte with Hazelnut Praline

If you're ever really, really bored, and you want a project that will take days to bring together, you might want to consider this cake.  Or, you can decide to make it for a family get-together, and somehow put everything together in the few hours you have after work before you totally collapse from exhaustion.  I of course picked the latter.

This cake is a lot of work.  And it requires some more advanced techniques.  I saw a lot of complaining in the comments section for this recipe, but I can confirm, it DOES work.  If you know what you're doing.  And it's absolutely amazing, like a giant tiramisu cake.  And the look on my sister's face when I brought this bad boy out of the kitchen was worth every miserable moment I spent piecing it together when all I really wanted was my bed.

White Chocolate Espresso Torte with Hazelnut Praline
From Bon Appétit magazine, December 2010

Praline and Chocolate Curls:
⅔ cup granulated sugar
¼ cup water
1½ teaspoons instant espresso powder
1 cup hazelnuts, toasted, husked
1 (6- to 8-ounce) block high-quality white chocolate (1 to 1½ inches thick, for chocolate curls)

Mousse:
12 ounces high-quality white chocolate (such as Lindt or Perugina), finely chopped
5 tablespoons water
2 cups chilled heavy whipping cream
2½ teaspoons instant espresso powder

Soaking Syrup and Ganache:
⅔ cup Kahlua or other coffee-flavored liqueur
4 teaspoons instant espresso powder
7 ounces bittersweet chocolate (do not exceed 61% cocoa), chopped
2 tablespoons dark corn syrup
¾ cup heavy whipping cream

Cake:
4 large eggs, at room temperature
⅔ cup granulated sugar
3½ teaspoons instant espresso powder, divided
1 teaspoon vanilla extract
⅛ teaspoon salt
1 cup sifted cake flour (sifted, then measured)
2 tablespoons (¼ stick) unsalted butter, melted, cooled
6 tablespoons powdered sugar, divided

Praline and Chocolate Curls

Place sheet of foil on work surface. Bring sugar and water to a boil in a heavy medium saucepan over medium-high heat, stirring until sugar dissolves. Boil without stirring until syrup is deep amber, brushing down the sides of the pan with a wet pastry brush and swirling occasionally, 7 to 8 minutes. Mix in espresso powder, then nuts. Scrape the mixture onto the foil; quickly spread out. Cool completely. Chop praline into small pieces.

Microwave white chocolate block at 50% power in 10-second intervals until the chocolate feels just slightly warm and is just beginning to soften (if too soft, let stand until firm enough to shave). Using a vegetable peeler, shave a 1- to 1½-inch wide ribbon, about 4 to 5 inches long, from the block. Gently roll the ribbon into a loose curl. Repeat, making 20 to 24 curls. (DO AHEAD: Praline and chocolate curls can be made 2 days ahead. Chill separately in airtight containers.)

Mousse

Stir chocolate and water in a metal bowl over a saucepan of barely simmering water until the chocolate is smooth. Remove the bowl from over the water. Cool the chocolate to lukewarm, stirring occasionally. Using an electric mixer, beat the cream in a large bowl until soft peaks form. Gradually pour the lukewarm chocolate over the cream, folding to blend well. Transfer 2½ cups of the mousse to another medium bowl; gently fold in the espresso powder. Cover and chill both bowls of mousse until firm, at least 6 hours. (DO AHEAD: Can be made 1 day ahead. Keep chilled.)

Soaking Syrup and Ganache

Stir liqueur and espresso powder in a small bowl until the espresso powder dissolves. Place the chocolate and corn syrup in a medium bowl. Bring the cream to a boil in a small saucepan; pour over the chocolate and corn syrup. Stir until melted and smooth. (DO AHEAD: Soaking syrup and ganache can be made 1 day ahead. Cover separately and store at room temperature.)

Cake

Preheat the oven to 350°F. Coat a 15x10-inch sheet of parchment paper with nonstick spray. Line a 15x10x1-inch baking sheet with the prepared parchment (sides of baking sheet should not be coated).

Combine eggs, sugar, 2 teaspoons espresso powder, vanilla, and salt in a large bowl. Using an electric mixer, beat until the egg mixture is thick and fluffy and falls in ribbons when the beater is lifted, 6 to 7 minutes. Sift the flour over in 3 additions, folding gently just to incorporate after each addition. Transfer 1 cup of batter to a small bowl; fold in butter. Fold the batter from the small bowl back into the batter in the large bowl just until combined; spread evenly on the baking sheet.

Bake the cake until a tester inserted into the center comes out clean and the cake begins to pull away from the pan, about 18 minutes. Cool the cake in the pan on a rack for 30 minutes.

Sift 2 tablespoons of powdered sugar over the cake. Cut around the pan sides. Slide a spatula under the parchment to loosen from the pan and invert the cake onto a work surface. Peel off parchment. Cut the cake crosswise into 4 rectangles, each about 10x3½ inches.

Place 1 cake rectangle on a platter. Brush 2 tablespoons of soaking syrup over. Spread 3 tablespoons of ganache over, then ⅓ of espresso mousse (about ¾ cup). Repeat 2 more times with cake, syrup, ganache, and mousse. Top with fourth cake layer; press lightly to adhere. Spread ⅔ cup plain mousse thinly over the top and sides of the torte to seal, then spread remaining mousse over top and sides. (DO AHEAD: Can be made 1 day ahead. Tent loosely with foil and chill.)

Before serving, press praline pieces into the mousse on all side of the torte. Mound white chocolate curls on the top. Mix 4 tablespoons of powdered sugar and 1½ teaspoons espresso powder in a small bowl. Sift over top of the torte.