Dark Chocolate Mousse Cake

Original inspiration can be found here

Chocolate Genoise

4 eggs
2 egg whites
125 g sugar
100 grams sifted all purpose flour
25 grams cocoa

Parchment line, butter, and dust with cocoa powder, a sheet pan (8x13)
Preheat oven to 350.

Combine eggs, whites and sugar in your stand mixer bowl. If
the eggs are fresh out of the fridge, place the bowl
over boiling water to heat them up just to room temp
(or leave the eggs out on the counter for a while). Once heated, whip with whisk
attachment until the mixture has tripled in volume -
watch the line of the mixture, it will rise and then
reach a point where it begins to fall again. At this
point remove from mixer and fold in the flour and cocoa powder. A Pour
into prepared pan and bake until done (about 20 minutes)

Release from pan and turn out unto towelled rack. Allow to cool completely. This can be made a day ahead. Just wrap well and store in the refrigerator.

With a long serrated knife, slice desired number of layers. (I also used a mold to cut squares about the size I wanted my cake to be)

Mousse

5 ounces bittersweet chocolate
2 tablespoons Grand Marnier
4 egg yolk
2 tablespoons cocoa
2 teaspoons grated orange rind
3/4 cup whipping cream -- whipped

Melt the chocolate and two tablespoons of Grand Marnier in a bowl set over a saucepan of simmering water. add the egg yolks one at a time, stirring each one well into the chocolate mixture before adding the next. After adding all the yolks, remove from the heat and allow to cool slightly.

Fold the cocoa and grated orange zest into the whipped cream, then fold the cream into the chocolate. Pour the mixture into a bowl and chill for several hours..

Divide the mixture according to number of layers. Mine was four layers of cake, so I did three layers of mousse, plus enough to coat the outside. I also made a simple syrup on brushed it on the layers before assembling. Pipe or spread mousse between each cake layer.

Blood orange Sauce
Peel and segment one blood orange. Juice a second blood orange. Stir in 1/4 cup cooled simple syrup. Marinate for a few hours. Spoon onto plate with cake.