Orange Chocolate Mousse Cake

• Preheat oven to 350° F. Prepare three 6-inch and two 5-inch pans. I use a pastry brush and cover pans generously with cake release.
• Place butter in a large saucepan and zest the orange directly onto the butter. Melt butter over medium-low heat and add cocoa, stirring until smooth. Whisk in the Orange Juice/Grand Marnier mixture and remove from heat.
• Add the sugar, sour cream, orange emulsion, and eggs to the warmed cocoa mixture and whisk until smooth.
• In a separate bowl, sift together the flour, baking soda, and salt. Add to the chocolate mixture, whisking until well blended.
• Pour batter into the prepared pans. Bake for 25-30 minutes, or until they feel firm to the touch and has slightly pulled away from the sides of the pan.
• Allow cakes to cool in pans on a rack for about 10 minutes.

To make the simple syrup:

• While cakes cool in the pans, combine the sugar and water in a small saucepan and bring to a boil, stirring until sugar is melted. Remove from heat and stir in the liqueur.
• Turn cakes out onto a wire rack. Use a pastry brush to moisten the tops of each cake with the syrup.
• Tip: I normally make my simple syrup ahead of time and store it in a spray bottle, in the fridge. A little trick I learned from a baking instructor.

To make the mousse:

• In a small bowl, whisk together the two egg yolks and half the sugar until smooth and creamy. Set aside.
• In a clean, grease-free bowl, whip up the egg whites and the remaining sugar to soft peaks. Set aside.
• Over low heat, bring the cream, milk and orange zest to a simmer in a saucepan. Remove from heat and pour through a sieve, or you may choose to skip this step and keep the zest in the mixture.
• While cream mixture is still warm, and add the chocolate callets. Stir until all the chocolate is melted and the mixture is even and smooth. You may need to return the saucepan to the heat if the cream mixture isn't warm enough. Stir in the liqueur.
• Add the egg yolk mixture to the chocolate mixture and stir immediate, so you don't risk cooking them.
• Fold the egg white mixture into the chocolate mixture until fully incorporated and smooth in texture. Refrigerate for a couple hours, or until set.

To make the frosting:

• Using a clean towel and some lemon juice or vinegar, clean your mixing bowl, whisk attachment and any utensils to remove any traces of grease.
• Fill a heavy duty pot about a quarter of the way with water and place on the stove over medium heat to simmer.
• Add egg whites, sugar and salt to the mixing bowl and place over the pot, ensuring the bottom of the bowl is not in contact with the water in the pot. Insert a thermometer into the egg white mixture and whisk continuously and gently, until temperature reaches 160°F.
• Once at the correct temperature, remove from heat and transfer mixing bowl to the stand mixer. With the whisk attachment, begin to whip the egg mixture until it becomes a thick, glossy, meringue and the bottom of the bowl is no longer warm to the touch. Do not begin adding butter while the bowl is still warm.
• Switch from your whisk to paddle attachment and with mixer on low speed, add butter cubes, one at a time, until incorporated. Continue to mix until it has reached a silky smooth texture.
• Add a pinch of crushed vanilla beans and orange emulsion, continuing to beat on low speed until well combined.

Assembly:

• Level and torte cakes, using a long serrated knife, or cake leveller.
• Use a pastry brush to soak each layer with the syrup.
• Top the first layer with mousse, place a layer of cake on top and repeat. The bottom tier has three layers and the top tier has two layers.
• Crumb coat with a thin layer of buttercream and refrigerate for about 15 minutes.
• Remove from fridge and cover with a generous layer of buttercream. It does not need to be perfectly smooth, as the overall design is meant to be antique.
• Arrange three bubble straws in a circle close to the centre of the bottom tier. Cut any pieces sticking out so that they are flush with the surface of the cake.
• Place the top tier on a cake board of the same size, or slightly smaller and using an offset spatula, place on top of the bottom tier. Adjust to centre and slide out the spatula.
• Pipe a shell border around the base of the top tier, using a small French tip and buttercream.
• Wrap both layers with sugar lace and finish with a simple lace flower. (see my post on how to make sugar lace here)