Black Pearl Layer Cake (a chocolate cake with wasaba and ginger)

note: this cake is very involved, and pretty exotic compared to other chocolate cakes but It is worth the time if you like the challenge of making a complicated cake and the excitement of trying something new.

INGREDIENTS

Black pearl ganache
6 ounces bittersweet (not unsweetened) or semisweet chocolate, chopped
3/4 cup heavy whipping cream
1.5 teaspoon ground ginger
2 tablespoon wasabi powder
2 tablespoons black sesame seeds
1 tablespoon corn syrup
2 tablespoons (1/4 stick) butter, room temperature

Ginger syrup
1 cup water
1/2 cup sugar
5 tablespoons matchstick-size or thinner strips peeled fresh ginger
1 vanilla bean, split lengthwise

Cake
2 cups boiling water
1 cup unsweetened cocoa powder
2 3/4 cups all purpose flour
2 teaspoons baking soda
1/2 teaspoon baking powder
1/2 teaspoon salt
2 1/4 cups sugar
1 cup (2 sticks) unsalted butter, room temperature
4 large eggs
1 tablespoon vanilla extract

Whipped cream frosting
2 cups chilled heavy whipping cream
1/4 cup plus 2 tablespoons powdered sugar
1/2 teaspoon vanilla extract
1/2 teaspoon ground ginger

(note: a simple buttercream frosting is also delicious on this cake, but if you choose buttercream be sure to refrigerate the assembled cake first so that the ganache is quite firm. This isn't necessary if you apply the recipe's light whipped cream topping.)

Additional black sesame seeds

PREPERATIONS

For black pearl ganache:
Place chocolate in medium bowl. Bring cream, ginger, and wasabi to boil in small pot. Pour hot cream over chocolate; cover with plastic wrap and let stand 15 minutes. Whisk cream and chocolate until smooth. Mix sesame seeds and corn syrup in small bowl to coat; stir into chocolate mixture. Let cool to lukewarm. Stir in butter. Cover and let stand at room temperature overnight to set.

For ginger syrup:
Place 1 cup water, sugar, and ginger in small saucepan. Scrape seeds from vanilla bean into pan; add bean. Stir over medium heat until sugar dissolves. Simmer 2 minutes; remove from heat. Let stand at room temperature 1 hour for flavors to blend.

Strain syrup into small bowl. Chop ginger. (Can be prepared 1 day ahead. Cover and refrigerate ginger and syrup separately.)

For cake:
Preheat oven to 350°F. Butter and flour three 8-inch-diameter cake pans with 2-inch-high sides. Line bottoms with parchment paper.

Whisk 2 cups boiling water, cocoa powder, and reserved chopped ginger in medium heatproof bowl. Whisk flour, baking soda, baking powder, and salt in large bowl. Using electric mixer, beat sugar and butter in large bowl until fluffy, about 1 minute. Add eggs 1 at a time, beating until incorporated after each addition. Beat in vanilla extract. Add flour mixture in 4 additions alternately with cocoa mixture in 3 additions, beginning and ending with flour mixture. Divide batter among prepared cake pans; smooth tops.

Bake cakes until tester inserted into center comes out clean, about 30 minutes. Cool in pans 5 minutes. Turn cakes out onto racks; cool completely. (Cakes can be prepared 1 day ahead. Wrap with plastic wrap and store at room temperature.)

For whipped cream frosting:
Beat cream in large bowl until soft peaks form. Add sugar, vanilla, and ginger. Beat until stiff peaks form.

Using long serrated knife, trim rounded tops off cakes to create flat surface. Place 1 cake layer, cut side up, on plate. Brush top with 1/3 cup ginger syrup. Spread half of ganache over top of cake. Place second layer, cut side up, atop first layer. Brush with 1/3 cup syrup; spread with remaining ganache. Top with third cake layer. Brush with remaining syrup. Spread sides and top with whipped cream frosting. Sprinkle top with black sesame seeds. Refrigerate until ganache is set, about 4 hours. Let stand at room temperature 30 minutes before serving. (Can be made 1 day ahead. Keep refrigerated.)

Makes 10 to 12 servings.