White and Dark Valrhona Chocolate Mousse Cake

**************************************************************************************

Love is a Many Layered Cake.

That's what I thought when I baked this for my husband's birthday last week. Despite the fact that we already bought an excellent Laurent Bernard chocolate cake for him earlier to celebrate with, I thought I should still bake something special for him.  After all, I always pull out all the stops for the kids birthdays and I thought it was only fair that SugahDaddy got a bit of effort too.  Deciding on the flavour was easy - he likes chocolate and macadamia nuts. It would have to be a boldly flavoured, 'solid' kind of cake and not light, fluffy and sissy (sorry no Chiffons then). And lastly, I love doing layered cakes, because they always manage to look so elegant, special and like something you bought from a chi-chi cake shop (and often for correspondingly less effort than you would think!).

I modified a Bon Appetit recipe on Epicurious, and the result was a 5-layered White and Dark Chocolate Mousse Cake, with alternating layers of white and dark chocolate eggless mousse and Kahlua-soaked chocolate genoise sponge, atop a crunchy macadamia chocolate crust (arguably the best part!).  The contrast between sweet white chocolate and bittersweet dark chocolate was very pleasing, and unlike a pure dark chocolate cake, you can many more slices of this cake as it doesn't feel as heavy.

Decorating the cake was easy - no need to smooth out icing all over the cake. All I did was dust the top all over with cocoa powder.  For this cake, leaving the sides of the cake exposed (instead of covered with icing) actually has a better aesthetic effect. I confess I really like those gold flakes they put on cakes which make them look so luxe. But they cost a bomb, and if like me you'd rather spend money on gold you wear, then well, here's something you might want to try: I sprinkled edible gold dust (from Wilton, cheaper than gold flakes!) in a rough zig-zag pattern over the cake, and also brushed some on the berries on top of the cake. Simple and elegant.

Did SugahDaddy like his cake? You bet. Happy Birthday Luv.

***************************************************************************

Recipe for White and Dark Chocolate Mousse Cake

Cake
1/4 cup (1/2 stick) (57g) unsalted butter
1 teaspoon vanilla extract
1/3 cup (40g) sifted all purpose flour (sifted, then measured)
1/3 cup (40g) sifted unsweetened cocoa powder (preferably Dutch-process; sifted, then measured)
4 large eggs
2/3 cup (150g) sugar

Macadamia crunch base
5 ounces (142g) dark chocolate chopped
1 cup paillette feuillettine 
1/3 cup macadamias toasted, chopped

Dark Chocolate Mousse
5 ounces (142g) white chocolate, chopped 
5 ounces (142g) dark chocolate, chopped
1 1/4 cups chilled heavy whipping cream
pinch of salt

4 tablespoons Kahlua liqueur for brushing on cake layers
Additional unsweetened cocoa powder for dusting on top cake layer
 

For cake:
Position rack in bottom third of oven and preheat to 350°F (176C). Line bottom of 9-inch-diameter cake pan with 2-inch-high sides with parchment paper. Melt butter in saucepan over medium heat. Remove from heat. Spoon off foam from top of butter and discard. Spoon clear yellow butter into small metal bowl, leaving water and milk solids in bottom of pan. Add vanilla to butter in bowl; set clarified butter aside.

Sift flour and cocoa powder together 3 times into medium bowl. Whisk eggs and sugar in large metal bowl to blend. Place bowl with egg mixture in large skillet of barely simmering water; whisk constantly until egg mixture is lukewarm (105°F), about 2 minutes. Remove bowl from water. Place bowl with clarified butter in hot water in same skillet over low heat to keep warm.

Using electric mixer, beat egg mixture until cool and tripled in volume, about 5 minutes. Sift 1/3 of flour-cocoa mixture over egg mixture and gently fold in with rubber spatula. Fold in remaining flour-cocoa mixture in 2 more additions. Fold 1 cup of cake batter into warm clarified butter until incorporated. Using rubber spatula, gently fold butter-cake batter mixture into remaining cake batter.

Transfer batter to prepared pan. Bake until tester inserted into center of cake comes out clean and top springs back slightly when gently pressed, about 30 minutes. Cool completely in pan on rack. (Can be made 1 day ahead. Cover; store at room temperature.)

Run knife between pan sides and cake to loosen. Invert cake onto rack; remove parchment. Using long serrated knife, trim top of cake horizontally, so that cake is level.  Split the cake into 2 layers. Set cake layers aside. 

For macadamia crunch:
Line bottom of 9-inch-diameter springform pan with parchment paper. Melt dark chocolate in a double boiler or in a microwave (being careful not to overheat it).  When chocolate is smooth and completely melted (it should look satiny), stir in pailette feuilettine and nuts. Spread crunch evenly over parchment in pan. Place one genoise cake layer atop crunch layer, pressing to adhere before the chocolate crunch layer cools down and solidifies. Chill until crunch is firm, about 1 hour.

For dark and white chocolate eggless mousse*:

Melt dark chocolate in a double boiler or in a microwave (being careful not to overheat it).  Stir slightly until melted chocolate is smooth. Cool chocolate to lukewarm. Do the same for the wite chocolate.

Using whisk attachment in electric mixer, beat cream and salt in another bowl until very soft peaks form (when bowl is tilted, cream should be fluffy but still pourable and flow to one side). Divide whipped cream into two equal portions. Pour one portion of whipped cream over and fold into dark chocolate just until incorporated. Pour second portion of whipped cream over and fold into white chocolate just until incorporated (mousse will be very soft).

Brush top of chilled cake layer with Kahlua.  Spread dark chocolate mousse over cake in pan. Place 2nd chocolate genoise cake layer over dark chocolate mousse. Brush top of 2nd layer with Kahlua, and spread white chocolate mousse on top. Dust the top with cocoa powder and chill overnight. (Can be prepared 2 days ahead. Keep chilled.)

Run knife between cake and pan sides to loosen. Soak kitchen towel in hot water; wring out water. Wrap hot wet towel around pan sides and hold 30 seconds. Carefully remove pan sides from cake; smooth mousse with knife if necessary. Place cake on pan bottom on rack set over baking sheet. Transfer to platter and serve. 

* You can use crushed vanilla wafers or rice cereal (which was in the original Bon Appetit recipe) as a substitute but the result will not be as good.

**This cake would be great with the usual chocolate mousse made with egg. In fact, the texture of regular mousse is smoother.  I used an eggless mousse (which is really the texture of whipped cream) as I can't consume raw eggs during pregnancy.