Sydney Opera House (Opera) Cake

Inspiration always comes to me in peculiar ways.  I recently began a large-ish project (I will share more later) and it made me think about a cake I made years ago.  It was a dome cake built in a bowl and I decorated it with some architectural-looking pieces of chocolate.  It reminded me a little of the Sydney Opera House. 

This past week I’ve been sifting through some favorite recipes and uncovered notes for coffee buttercream.  This made me think of Opera Cake since coffee buttercream is a component.  I consider it a very architectural cake since it is built from the ground up in layers of delicious almond sponge cake.  I decided to revise my previous cake into a more literal form; and to be perfectly honest, I really like the play on words!

I decided to add a chocolate Sydney Harbour Bridge.  I realize it’s not geographically where it should be in reference to the Opera House, so please forgive me that small inaccuracy.  Just consider this a Sydney-inspired cake. 

The bridge is made of melted chocolate bark.  I melted one brick in the microwave for about 1 minute and transferred it to a disposable piping bag.  I found a small picture online of the Sydney Harbour Bridge and printed it out.  I used it as a template under a sheet of parchment paper.  This is not something I could have free-handed, and even though my hand was a little shaky this morning, I think it turned out okay!

I constructed the Opera House pieces out of gum paste.  I first experimented with just a simple silhouette, but immediately decided that it should be 3D.  Even though I didn’t use the silhouette, I like it and will probably eat it later.  🙂

I figured an opera cake should have ruffles.  My brain thinks opera=fancy.

But, enough about the decor, right?  The cake is downright delicious with layers of almond sponge cake drenched in coffee then layered with coffee buttercream and glazed with bittersweet chocolate ganache (the description is worth the run-on sentence).  I had a little extra coffee buttercream, so I used it for the edge ruffle.  I’ve re-worked the recipe for a smaller quantity of servings.  This cake easily serves 4.

The recipe seems a bit lengthy, but once you get the almond sponge cake baked the rest comes together pretty quickly.

Opera Cake  [click for printable version]

Serves 4

Almond Sponge Cake:

2 eggs, room temperature

1/2 cup confectioners’ sugar

1/2 cup almond flour

1/8 cup all purpose flour

2 egg whites, room temperature

1/8  tsp. cream of tartar

2  tbsp. extra fine granulated sugar

Preheat the oven to 425 degrees. Grease a  12×16 sheet pan with shortening. Line with parchment and grease parchment paper. Set aside.

Combine the 2 whole eggs, confectioners’ sugar and almond flour in a bowl. Combine with a hand-held mixer until batter has lightened considerably in color (should be a pale yellow). Set aside.

Whip the egg whites in a clean bowl on low speed until they start to froth. Add the cream of tartar and increase mixer speed, whipping until stiff peaks form. Add the 2 tbsp. granulated sugar and whip for a few seconds longer to incorporate.

Sift the flour over the pale yellow egg mixture, then scoop about ⅓ of the egg whites into the egg mixture and fold together gently with a rubber spatula. Add the remaining egg whites and fold in until uniformly mixed.

Pour the batter into the sheet pan and distribute it evenly with an offset spatula, making the layer as level and smooth as possible.

Bake for about 5 to 8 minutes until the cake is just firm.

Remove from the oven and turn out cake onto a cooling rack. Remove parchment. Allow to cool slightly. Cut cake into four even pieces.

Coffee Buttercream:

2 cups powdered sugar

1 stick of softened butter

Pinch of salt

1/2 tsp. vanilla extract

2 tbsp. milk

1/2 tsp. instant coffee or espresso powder

1 tbsp. hot water

Cream sugar with butter and salt in large bowl. Blend in extract and milk into mixture. Mix instant coffee in 1 tablespoon hot water. Gradually stir in coffee to desired taste.

Chocolate Ganache Glaze:

1/4 cup heavy cream

1/4 cup bittersweet chocolate chips

Heat heavy cream in microwave for 1 minute, or until cream is hot but not boiling.  Mix chocolate pieces in and stir until completely  melted.  Allow mixture to cool to room temperature.

Assembly:

1/4 cup strongly brewed coffee

Brush three almond sponge cake layers liberally with coffee.  Frost the same three pieces with buttercream mixture and stack.  Top with plain layer.  Glaze with room temperature chocolate ganache.   Let chill in refrigerator for 30 minutes.  Trim edges evenly with a serrated knife and decorate as desired.