Master Class: Raspberry Charlotte Royale

The secret of this dessert — a sliced jelly roll filled with mousse — is a flexible cake that’s a cross between a genoise and a classic sponge.

While standard charlottes depend on bread, ladyfingers, or plain cake, the impressive Charlotte Royale uses spirals of jam-filled jelly roll to encase a mousse filling. Despite its impressive appearance, though, this dessert is not particularly difficult to make. To simplify it even further, Susan Purdy, author of A Piece of Cake (Macmillan, 1989) and Have Your Cake and Eat It, Too (Morrow, 1993), created a cake specifically designed to hold its shape while being rolled up.
Like the classic French genoise, Purdy’s cake relies on beaten egg foam for its light, airy texture. Nevertheless, there are differences between the two cakes. To begin with, a genoise is made by warming whole eggs with sugar and beating air into the whole mass. In Purdy’s cake, the egg yolks and whites are beaten separately with sugar; this process builds elasticity and flexibility in the batter, resulting in a cake less likely to crack during rolling.
This cake also differs from conventional American sponge cakes, which use baking powder to achieve a high rise and a rather coarse crumb. To give her cake a denser, stronger texture more suitable for rolling, Purdy relies solely on the egg foam for rise, omitting chemical leaveners. In addition, Purdy adds cornstarch to the cake flour in the recipe, creating a very low-protein mixture that yields an extremely tender crumb. The resulting delicacy of the batter makes it important to fold in the dry ingredients gently, by hand, to avoid breaking the air bubbles in the egg foam. By adding the dry ingredients in small amounts, the cook can incorporate each portion with minimal mixing.
To promote tight rolling, trim the crisp edges and roll the cake in a sugared tea towel as soon as it comes out of the oven. Once the cake has been unrolled, coated with preserves, and rerolled, slices are used to enclose a gelatin-based mousse enriched with whipped cream. The mousse can be made with one cup of any fruit puree, including mangoes, passion fruit, cherries, or berries of any type. If you choose to make your mousse with a fruit other than raspberries, be sure to use a complementary jam in the cake (apricot is fairly neutral and can be used with tropical fruits), and serve the dessert with a sauce made from the same fruit that is used in the mousse.
For additional variations, instead of vanilla, the cake can be scented with an equal amount of lemon or orange extract or one tablespoon citrus juice plus the grated zest of one fruit.
If you wish, you can use this versatile cake as a simple jelly roll, rather than as the base for a Charlotte Royale. To do so, simply follow the recipe instructions through step 5, then dust the top with sifted confectioner’s sugar and garnish with whipped cream.

RASPBERRY CHARLOTTE ROYALE
Serves 8–10
The entire charlotte can be prepared and refrigerated a day in advance of serving. Or, freeze the unsliced jelly roll until you are ready to assemble the charlotte. You can speed up the process of setting the gelatin for the mousse by chilling it in an ice-water bath, which takes about 15 minutes, as opposed to one hour in the refrigerator. If the mixture becomes too stiff, place the bowl in a hot-water bath and whisk briefly until the consistency of soft pudding is achieved.

Raspberry Jelly Roll Cake

1/2 cup sifted cake flour
1/4 cup sifted cornstarch
4 large eggs at room temperature,
separated
Pinch of salt
10 tablespoons sugar
3/4 teaspoon vanilla extract
1/4 cup confectioners’ sugar
2/3 cup raspberry preserves

Raspberry Mousse Filling

1 tablespoon unflavored gelatin
1 1/2 tablespoons juice from 1/2 lemon
1/4 cup sugar
Pinch of salt
1 pint fresh raspberries or 12 ounces frozen, unsweetened raspberries, thawed, pureed, and strained (1 cup)
3 tablespoons fruit liqueur, such as Framboise (optional)
3/4 cup chilled heavy cream

Raspberry Sauce
1 pint fresh raspberries or 12 ounces frozen unsweetened raspberries, thawed, pureed, and strained (1 cup)
3 tablespoons sugar
1 tablespoon juice from 1/2 lemon
2 tablespoons fruit liqueur to match filling (optional)

Fresh raspberries for garnish

1. For the jelly roll, adjust oven rack to low position and heat oven to 350 degrees. Sift flour and cornstarch together; set aside. Beat egg whites and salt in bowl of electric mixer on medium speed until frothy. Gradually add 6 tablespoons sugar, beating constantly, until mixture is stiff and glossy but not dry; set aside.
2. Without washing beaters, beat yolks and remaining 4 tablespoons sugar until thick and light in color, stopping machine and scraping down bowl and beaters twice. Add vanilla; beat on medium-high speed until yolks form a flat ribbon that falls back on itself when beaters are lifted, 3 to 5 minutes.
3. Fold 1/3 of whites into yolk mixture. Sprinkle about 3 tablespoons of dry ingredients over batter; fold in gently. Repeat with small additions of dry ingredients. Near end of folding in dry ingredients, alternate with some of whites. Finally, fold in remaining whites to form a light, smooth batter.

4. Turn batter into a greased 15-by-10-inch jelly-roll pan lined with greased and floured parchment; smooth batter with a rubber spatula. Bake until top is golden and feels springy to the touch and edges begin to pull away from pan, 12 to 15 minutes. (Do not overbake or cake will be dry.)
5. Meanwhile, sift confectioners’ sugar over a tea towel measuring at least 15-by-10-inches. Immediately invert baked cake onto sugar-covered towel and peel away paper. Follow illustrations 1 through 3 to make jelly roll.
6. Set finished jelly roll seam side down. With a serrated knife, cut cake into 1/3-inch thick slices, and cut 3 slices into half-circle wedges, cleaning knife after each cut to keep preserves from smearing cake. Line a 1 1/2-quart bowl with plastic wrap. Line bowl with cake slices; use another slice to fill holes.
7. For the mousse, combine gelatin and 1/4 cup cold water in a small saucepan; let stand to soften gelatin, about 2 minutes. Stir in 1/2 cup hot water, lemon juice, sugar, and salt; cook over low heat, stirring constantly, until sugar and gelatin dissolve. Stir in berry puree and liqueur; refrigerate or set in ice-water bath, whisking occasionally, until mixture thickens to consistency of raw egg whites.
8. Whip chilled cream to soft peaks; fold into mousse. Spoon filling into cake-lined bowl; cover top with remaining cake slices and scraps. Bring draped plastic wrap over cake pieces, then cover with another piece of plastic. Refrigerate at least 3 hours or overnight.
9. For the sauce, mix all sauce ingredients together in a small bowl; refrigerate until ready to serve.
10. To unmold charlotte, remove plastic wrap and fold back flaps of inner wrapping. Cover charlotte with a cake plate and flip charlotte onto plate. Peel off plastic and garnish with berries. Cut charlotte into wedges and serve on individual plates with sauce.

January, 1994