This Double Chocolate Mousse Cake was one of our premier offerings. Both white chocolate and dark chocolate mousse team up with a deeply chocolate, yet light textured chocolate chiffon cake. The Double Chocolate Mousse Cake is beautiful, light and easy to make and while full of flavor is not overwhelming sweet.
After much testing, I came to the conclusion that chiffon cakes, because they use oil and not butter, have a longer shelf life than do butter cakes. While the majority of our wedding cakes were butter cakes, if the cake was to be sold to our wholesale clientele or needed a shelf life, it was made with a chiffon cake or an oil based cake.
Chiffon cakes are one of the easiest cake to make. Basically, the dry ingredients are mixed together and the wet ingredients, except for the egg whites and a bit of sugar, are placed in the mixing bowl. The dry ingredients are plopped on top and they are beat together. No creaming or adding the flour in stages. The only other thing is to beat the whites with the sugar and fold all of it together. This Double Chocolate Mousse Cake is extremely dark in color and moist, providing a counter point to the white chocolate mousse filling and the dark chocolate mousse finish.
One of my favorite customers has a son, Sean, who had this Double Chocolate Mousse Cake for every birthday. I would always sent him a few truffles as my gift.
The chocolate mousse used to finish the cake is a bit tricky to reconstitute. After it has been chilled, it has to be heated slightly and slowly to get it to the consistency where it can be spread. It is important to heat it a bit at a time, then stir it. I used a hair blower on high to heat the outside of the bowl as well as the top of the mousse. I would stir it, then heat it again until it became smooth and spreadable. The bowl could also be placed over hot - not boiling- water briefly, removed and stirred. Just be patient with this step so you don't liquify it completely.
The Double Chocolate Mousse Cake, while stored in the refrigerator holds well at room temperature. It can also be frozen in its entirety for up to a month. Just transfer it to the refrigerator a day or two before serving to thaw. Be sure to freeze it before covering and cover with foil loosely so as not to mar the finish. If you have a container it will fit into or a box that would be another solution.
The cake layers for the Double Chocolate Mousse Cake can also be made ahead and frozen several months ahead if well wrapped. Again, freeze them before you wrap.
Please note the dark chocolate mousse uses raw eggs yolks and egg whites, so it may not be advisable for the very young or very old. At 76, I still eat this Double Chocolate Mousse Cake. In fact, I look for excuses to make it.
Chocolate Chiffon Cake for the Double Chocolate Mousse Cake1 cup cocoa (85 grams or 3 ounces)
1 cup sifted cake flour (100 grams or 3 ½ ounces)
¾ cup sugar (150 grams or 5 ⅓ ounces)
1 teaspoon baking soda
¾ teaspoon baking powder
4 egg yolks
¾ cup oil
½ cup water
1 teaspoon vanilla
¾ cup egg whites (160 grams or 5 ⅔ ounces or about 5 egg whites)
¾ cup sugar (150 grams or 5 ⅓ ounces)
Spray the center only of three 9x2 inch round cake pans and line with parchment. Spray the center of the paper only. Set aside. Preheat the oven to 350 degrees.
Sift the cocoa into the cake flour, ¾ cup sugar, baking soda and baking powder. Whisk together and set aside.
Place the egg yolks, oil, water and vanilla in a mixing bowl. Place the dry ingredients on top. Beat on medium for two minutes. Scrape down and mix on low until smooth.
In a clean bowl fitted with a whisk attachment, whisk the whites on medium high until soft peaks form. Add the sugar in a slow, steady stream and beat to medium peaks. Do not overheat the whites. It is best to underbeat rather than overbeat. Stir ⅓ of the whites into the chocolate mixture. Fold in the remaining whites. Divide among the three pans (300 grams or 10 ounces each). Spread the batter evenly in each pan. Bake 14 to 16 minutes until a tester comes out clean or the layer springs back when lightly touched. Do not overbake or they can become dry.
Yield: 900 grams or about 31 ½ ounces. Layer size: 1 ½ inches each.
White Chocolate Mousse6 ounces white chocolate (170 grams)
⅓ cup 40% or heavy cream
1 ½ cups 40% or heavy cream
Combine the white chocolate and ⅓ cup cream in a small bowl. Make a double boiler by placing it over a pan of hot water at a simmer. Do not let the water boil. Heat to melt the chocolate. Whisk to combine. Cool until it begins to thicken slightly.
Beat the remaining cream to the chantilly stage. Fold the white chocolate and the whipped cream together.
Yield: 590 grams or 20 ounces
Dark Chocolate Mousse9 ounces of semisweet chocolate (255 grams)
½ pound butter (225 grams or 2 sticks)
4 egg yolks
¾ cup 40 % or heavy cream
4 egg whites
½ cup sugar (100 grams or 3 ½ ounces)
In a large bowl, over simmering water, melt the chocolate and the butter. This may be done in a microwave if desired. Whisk until smooth. Cool to lukewarm. Whisk in the egg yolks.
Beat the cream to the chantilly stage. Set aside.
Beat the whites until the whisk leaves a trail. Add the sugar gradually andbeat to medium peaks. Stir about 25% into the chocolate mixture to lighten it. Fold the remainder of the whites into the chocolate mixture along with the cream. Chill.
Yield: Approximately 2 quarts or 890 grams or 31 ¼ ounces.
This is the trickiest part of this cake. The mousse will be unusable as is but it must be heated and stirred gently and with patience so it doesn't melt completely. When ready to use, heat the outside of the bowl with a hair blower or set it over hot water briefly. Stir to soften. Repeat the heating and stirring until it is soft enough to frost the cake.
Assembly of the Double Chocolate Mousse Cake
3- 9” Layers Chocolate Chiffon Cake
White Chocolate Mousse Filling
Dark Chocolate Mousse Frosting
Place one layer of cake in the bottom of a 9x3 inch cheesecake pan.Spread with half the white chocolate mousse (about 285 grams or 10 ounces). Place the second layer of cake on top then remainder of the mousse. Top with the third layer of cake. Freeze overnight.
Place the cake on a fat can and release it by heating the sides with a blow dryer and sliding the side down.Transfer the cake to a cardboard cake round. Frost the sides and top. Comb the sides of the cake Clean the bottom of the board with a piece of paper towel wrapped around your finger or use a spatula. Finish the top with a #5B tip forming a running "e" design.
Store the Double Chocolate Mousse Cake in the refrigerator. Bring to room temperature to serve.
Yield: Cut into 14 to 16 servings.