Gateau Concorde

Chocolate wafer-roll cake arranged in a circle on a white plate, with crumbs scattered nearby on a light countertop

This cake’s structure is deceptively simple: three disks of chocolate meringue layered with and encased in chocolate mousse, finished with a coat of broken meringue strips that give the exterior its distinctive texture. Cocoa and confectioners’ sugar are folded into the beaten whites in three careful additions until just combined. Overmix and the meringue can deflate and spread; under-mixing leaves streaks of cocoa that bake unevenly. But don’t let that intimidate you! Meringue is more forgiving than its reputation suggests. Pipe the strips with even pressure and let them naturally fall from the bag rather than pressing down flat—this preserves their round cross-section and ensures they bake through evenly.

Gateau Concorde

Makes 1 (8-inch) cake

Ingredients
  

Meringue:

  • 2 cups (240 grams) confectioners’ sugar
  • 1 cup (85 grams) unsweetened cocoa powder
  • 8 large egg whites (240 grams), room temperature
  • 1¾ cups (350 grams) granulated sugar
  • ¼ teaspoon kosher salt

Mousse:

  • 6 ounces (170 grams) 64% cacao bittersweet chocolate, chopped
  • 3 tablespoons (45 grams) heavy whipping cream, room temperature
  • 4 large egg whites (120 grams) (see Note), room temperature
  • ¼ teaspoon kosher salt
  • 10 tablespoons (120 grams) granulated sugar
  • 1¾ cups (420 grams) cold heavy whipping cream

Instructions

  • For meringue: Preheat oven to 225°F (105°C). Using a dark marker, trace 2 (8-inch) circles on a sheet of parchment paper, and place, ink side down, on a baking sheet. Trace another 8-inch circle on another sheet of parchment paper, and place, ink side down, on another baking sheet.
  • In a medium bowl, whisk together confectioners’ sugar and cocoa.
  • In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites at medium speed until soft peaks form, 3 to 4 minutes. With mixer on medium speed, add granulated sugar in a slow, steady stream; increase mixer speed to medium-high, and beat until stiˆ peaks form and sugar fully dissolves, 4 to 5 minutes. Sift confectioners’ sugar mixture onto egg mixture in three additions, folding just until combined after each addition. Spoon meringue into a pastry bag fitted with a ½-inch round piping tip (Ateco #806).
  • Starting from center of each drawn circle, pipe meringue in a spiral to fill each circle. Pipe remaining meringue in long strips in remaining space on prepared pans. (Try to keep pressure on the pastry bag as even as possible and let the meringue fall from the bag as opposed to pressing it into the parchment to keep its tubular shape. Make sure the strips are not too thin or too thick, as this will result in an uneven bake.)
  • Bake until completely dry and set and meringue strips easily pull away from parchment, about 1 hour. Turn oven off, and let meringues cool in oven for 1 hour. Cooled meringues can be stored in airtight containers for up to 2 days.
  • For mousse: In the top of a double boiler, heat chocolate over simmering water, whisking frequently, until melted. Remove from heat, and whisk in room temperature cream.
  • In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites and salt at medium speed until soft peaks form. With mixer on medium speed, gradually add granulated sugar; increase mixer speed to medium-high, and beat until stiff peaks form, 3 to 4 minutes. Transfer to another bowl.
  • In the bowl of a stand mixer fitted with the whisk attachment (bowl and whisk do not need to be cleaned between), beat cold cream at mediumspeed until stiff peaks form. Add whipped cream to chocolate mixture, folding until combined. Add egg white mixture, folding until combined and no streaks remain. Use immediately.
  • Remove cooled meringue strips from parchment paper. Using a sharp paring knife, cut meringue strips into 2-inch pieces.
  • Using a large offset spatula, place 1 meringue disk on desired serving platter. Spread 1½ cups (about 270 grams) mousse on top of meringue. Top with second meringue disk, and spread 1½ cups (about 270 grams) mousse on top. Top with remaining meringue disk. Spread remaining mousse on top and sides of cake. Arrange meringue strip pieces on top and sides of cake as desired. Refrigerate for at least 4 hours or up to overnight before serving. (The long chill helps to soften the meringue layers and make them easier to slice.) Cut with a serrated knife. Refrigerate in an airtight container for up to 2 days, but best served within 1 day.

Notes

Note: Since consuming raw or undercooked eggs may increase your risk of foodborne illness, you may substitute pasteurized egg whites.
Tried this recipe?Let us know how it was!
Previous articleCitrus Pound Cake
Next articleKey Lime Thumbprint Cookies

This site uses Akismet to reduce spam. Learn how your comment data is processed.