For the meringue cake layers:
- 6 egg whites, aged (see the recipe)
- 1 1/8 cup (225 g) granulated sugar (#1)
- 1/4 cup (50 g) granulated sugar (#2)
- 6 1/2 tablespoons (50 g) all-purpose flour
- 1 1/3 cups (175 g) toasted hazelnuts
- 1 teaspoon vanilla sugar
For the Charlotte cream:
- 1 cup + 3 1/2 tablespoons (275 g) unsalted butter, room temperature
- 6 egg yolks, cold
- 3/4 cup (150 g) granulated sugar
- 2/3 cup + 2 teaspoons (175 g) whole milk 3.2% fat
- 1 1/3 tablespoons (10 g) cocoa powder
- 1 teaspoon vanilla sugar
- 1 tablespoon cognac