Devil's Food Cake with Black Pepper Boiled Icing

Combine chocolate and salt in a large bowl; place a fine-mesh strainer over bowl and set aside.

Pour 1 tablespoon cream into a small bowl.

Sprinkle gelatin over and let stand until softened, about 10 minutes. Meanwhile, bring remaining cream and 1 tablespoon sugar to a simmer in a small saucepan, stirring to dissolve sugar.

Whisk yolks and remaining 1 tablespoon sugar in a medium bowl. Gradually whisk in hot cream mixture; return to saucepan. Cook over medium heat until mixture thickens slightly and your finger leaves a path on the back of a spoon when drawn across, about 3 minutes.

Remove from heat.

Add gelatin mixture to cream mixture; stir to dissolve.

Pour through prepared strainer into chocolate.

Let stand for 1 minute; whisk until chocolate is melted and mixture is smooth.

Whisk in crme frache. Using an electric mixer, beat filling until well blended, about 2 minutes. Press a sheet of plastic wrap onto surface of filling; chill overnight. Preheat oven to 35

Coat the bottom and sides of three 9" cake pans with nonstick spray. Line bottom of pans with parchment-paper rounds. Sift cocoa powder into a medium bowl.

Whisk in egg and egg white. Gradually whisk in 1/2 cup plus 2 tablespoons lukewarm water; whisk until smooth. In a separate medium bowl, whisk both flours and next 2 ingredients. Using an electric mixer, beat brown sugar, butter, vanilla, and salt in a large bowl, occasionally scraping down sides of bowl, until smooth, about 2 minutes. Gradually beat cocoa mixture into butter mixture. Beat in flour mixture in 3 additions, alternating with buttermilk in 2 additions, beginning and ending with dry ingredients. Fold in cocoa nibs and ground espresso. Divide batter among pans; smooth tops.

Bake cakes until a tester comes out clean when inserted into center, about 17 minutes.

Let cakes cool in pans set on wire racks for 5 minutes. Invert cakes onto racks; remove pans and let cakes cool completely. DO AHEAD: Can be made 1 day ahead. Wrap cakes individually in plastic wrap and store at room temperature.

Place 1 cake layer on a plate. Stir filling to loosen.

Spread half of filling (about 1 cup) over cake in an even layer.

Place second cake layer on top of filling.

Spread remaining filling over in an even layer.

Place remaining cake layer on top. Chill cake for 1 hour.

Mix 1 tablespoon sugar and salt in a small bowl; set aside. Attach a candy thermometer to side of a small saucepan; add remaining sugar and 1/2 cup water to pan. Stir over medium-low heat until sugar dissolves. Increase heat and boil without stirring, occasionally swirling pan and brushing down side with a wet pastry brush, until thermometer registers 240, about 10 minutes. Meanwhile, place egg whites in the bowl of a stand mixer fitted with a whisk attachment. Beat at medium speed until frothy. With machine running, gradually add reserved sugar and salt from small bowl. Gradually add hot syrup from saucepan to egg whites, beating at medium-high speed and allowing syrup to drizzle down sides of bowl. Continue beating whites until stiff and cool, about 20 minutes.

Add pepper; beat until well blended. Immediately spoon topping onto cake. Smooth over top and sides. Working quickly, swirl icing decoratively. DO AHEAD: Cake can be iced 1 day ahead. Cover with a cake dome; chill.

Let frosting layers set fully before adding the next layer of cake. You may use an 8" cake pan for thicker layers.