Asian Strawberry Mousse Sponge Cake

I made this cake as a birthday cake last weekend. It is an Asian inspired cake - like those fresh fruit cakes from Asian bakeries with the really light sponge cake and not too sweet whipped cream frosting. I am very unfamiliar with Asian baking but also very interested in honing my skills. I'm pretty happy with how this turned out. My only regret is not having any pictures of the sliced cake. It was a magnificent 4 layer cake filled with pale pink strawbweey mousse. It must have been yummy because it disappeared too quickly for me to take any photos!

The recipient of this cake is someone I dated for a couple of years back in 2003-2005 and now he's become one of my best friends. Him and my son get along amazingly well and Zach is lucky to have someone as amazing as this guy in his life. I'm glad I could do something special for his birthday.

The recipe is adapted from Viet World Kitchen. I made 2 batches of the sponge cake and cut each cake into 2 layers for a total of 4 layers.

Asian Sponge Cake
Makes 1 one 9" round cake

Egg yolk base:
3 large egg yolks, placed in a metal bowl, about 3-quart capacity
1/2 cup sugar
1 1/2 teaspoons pure vanilla extract

Egg whites:
3 large egg whites, place in a metal bowl, 2-3-quart capacity
pinch of salt
1/4 teaspoon cream of tartar
1 1/2 tablespoons sugar

Finishing the batter:
1/3 cup plus 1/4 cup cake flour, sifted
3 tablespoons unsalted butter (melted and cooled)

1. Grease, flour and line the bottom of a 4-cup pan such as a round 9" pan. Put oven rack in the lower third of the oven and preheat to 350 degrees F.
2. Beat the egg yolks in a bowl with electric mixer. Gradually sprinkle in the sugar by the tablespoon to incorporate well. (Do this too fast and the batter will be grainy with sugar.) Continue beating for several minutes, until the mixture is thick, pale yellow, and when you pause and lift the whisk (or beaters), the batter drips down and forms a ribbon that slowly dissolves on the surface. Beat in the vanilla. Set aside. Wash and dry the beaters well.
2. Start beating the egg whites in a separate bowl. When they are foamy throughout, sprinkle in the salt and cream of tartar. Continue beating until soft peaks form (when the whisk (or beaters) is lifted out of the egg whites, a soft, slightly bent over peak of egg white forms in the bowl). As you beat, the whites will go from clear to light grey to solid white. Instead of sliding from the walls of the bowl, they will stick to the bowl.
3. After soft peaks form, sprinkle in the 1 1/2 tablespoons sugar and continue beating for a couple more minutes to generate stiff egg whites (the peak stands straight when the whisk is lifted from the bowl). The whites will have a sheen.
4. Immediately take a large rubber spatula and add 1/4 of the egg whites into the egg yolk base. Stir gently to lighten the base. Then add 1/3 of the remaining whites onto the base. Sift 1/4 of the flour on top. Delicately and quickly use the spatula to fold the ingredients together, until they are nearly all incorporated. Repeat another 2 times, alternating flout and whites as before. When all ingredients have been added and folding in is almost complete, pour in the melted butter and fold it in quickly (do not overblend or the batter will deflate). The finished batter will be pale yellow, very thick, and light.
5. Pour the batter into the prepared cake pan. It should fill to about 1/4 inch of the rim. Scoop out extra batter to avoid overflow during baking. Use the spatula to spread the batter out evenly. Push the batter toward the edges to prevents a domed-center during baking.
6. Gently slide the cake into the oven. Bake for 20 to 25 minutes. The cake will rise slowly and then brown. The cake is done when its puff sinks slightly and the sides show a faint line of shrinkage from the edges of the pan. Remove the cake from the oven and cool on a rack for 15 minutes. (It will deflate and pull away from the pan walls.) Run a knife all around the edge, between the cake and the pan. Invert the cake onto your hand (or back on the rack), give the cake bottom a tap, and then remove the cake pan. Peel off the parchment paper and discard. Invert the cake, top side up, onto the rack. Allow to cool completely (about 1 hour) before eating, filling, or icing.

Mousse & Assembly

2 tablespoons Grand Marnier, Cointreau, or Triple Sec
1 1/4 teaspoons unflavored gelatin
1 pint strawberries
1/4 cup sugar
1/2 cup heavy cream, chilled

Whipped cream frosting:
1 1/2 cups heavy cream, chilled
2 tablespoons sugar
1/2 teaspoon vanilla extract

1. Cut each cake in half horizontally, forming your layers.
2. To make the strawberry mouse, put the liquor in a small bowl and sprinkle the gelatin over it. Set aside.
3. Wash and pat the strawberries dry with a dish towel. Hull and cut enough berries into small pieces about the size of your thumbnail to make a brimming cup. Set aside the remaining strawberries for garnish.
4. Put the strawberries in a small skillet and add the sugar, stirring to combine. Heat over medium heat, stirring just until the sugar has melted. Remove from the heat and add the liquor, stirring, until the gelatin has dissolved. Pour into a mixing bowl and set aside to cool to room temperature, about 1 hour, stirring occasionally. When the berries have sufficiently cooled, you will be able to mound them with the liquid into a jam-like mixture.
5. While the strawberry mixture cools, whip the 1/2 cup cream using a stand mixer or hand-held mixer until soft peaks form. (Aim for a soft, thick marshmallowlike texture.) Refrigerate until ready to use.
6. For the frosting, combine the cream, sugar and vanilla in a bowl. Then whip using a stand mixer or hand-held mixer until just shy of stiff. Lift up the beaters and nice peaks should form, clinging onto the beaters nicely.Do not overwhip or it will be grainy. Refrigerate until ready to use.
7. To fill and frost the cake, put the cake on a cake stand or platter, with strips of wax paper or parchment paper underneath to form a collar that will keep the stand or platter dirty clean. Finish the strawberry mousse by combining the strawberry mixture with the 1/2 cup of whipped cream; a rubber spatula is a great tool to use. Spread the strawberry mousse on top of the cake layer. Place the second layer atop. Then frost the cake with the whipped cream. When finished decorating, refrigerate the cake for 10 to 15 minutes, then gently pull out the pieces of wax or parchment paper. The cake can be decorated up to 3 hours in advance. Serve with the remaining strawberries on the side.