Source: “The All-Purpose baking cookbook” de The King Arthur Flour Baker’s Companion

One 8- or 9-inch cake, 12 portions

Ingrédients

Cake (cf recette de génoise)

Filling

• 3 (3 1/2) cups unsweetened frozen raspberries
• 1 cup sugar
• 1 tablespoon lemon juice
• 1 1/2 teaspoon unflavored powdered gelatin
• 1/4 cup cold water
• 1 cup heavy cream (35%)

Syrup

• 1 cup sugar
• 1 cup water
• 3 à 4 c. à table kirsh (flavoring optional)

Frosting

• 1 1/2 cup heavy cream (35%)
• 1 teaspoon vanilla extract
• 1/4 cup confectioners’ sugar
• 1/2 pint (4 onces) fresh raspberries, for garnish (optional)

Directions

For the filling

1. Bring the frozen raspberries, sugar, and lemon juice to a simmer in a medium-sized saucepan set over medium heat.
2. Remove from the heat and press the fruit through a fine strainer; discard the seeds and any solids, reserving the purée.   Set it aside to cool to room temperature.  You shouls have at least 1 1/2 cups.
3. In a small heatproof bowl or measuring cup, combine the gelatin and cold water.  Let the mixture sit until all of the water has been absorbed (this only takes a minute or so).
4. Whip the cream until soft peaks form; set it aside.
5. Heat the gelatin-water mixture over low heat until it becomes a clear liquid.  Stir this into the raspberry purée, then fold in the whipped cream.
6. Refrigerate the mousse for about 90 minutes, to let it begin to set up.

For the Syrup

1. Bring the sugar and water to a boil, stirring until the sugar dissolves.
2. Remove from the heat, allow to cool, then store in the refrigerator until you’re ready to use.
3. Flavor syrup with kirsh.

To assemble the cake

1. Slice the cake layer horizontally into the even rounds.
2. Place one of the rounds on a serving plate, cut side up, and brush with the simple syrup.
3. Spread half the raspberry mousse on this layer, then place the second round, cut side up, on top.  Don’t worry if the mousse seems a little soft; once the cake is assembled it will continue to firm up in the refrigerator.
4. Brush with syrup, then top the it with the remaining mousse.
5. Place the last cake layer on top, cut side down, and brush with the any remaining syrup.
6. Refrigerate the cake for 1 hour before finishing.

For the frosting

1. Whip the heavy cream, vanilla, and confectioners’ sugar until soft peaks form (overwhipping will create grainy lumps).
2. Cover the sides and top of the cake with whipped cream, decorating the top with fresh raspberries.
3. Refrigerate for another hour before serving.