Opera Cake

Opera Cake

Opera Cake

One of Patrick’s favourite things to do in the kitchen is make buttercream and decorate cakes – he even has an entire instagram page devoted to his cake decorations (Check it out here: www.instagram.com/pogicakes). So when we decided to bake a cake for a friend, buttercream was at the forefront of our minds. This decadent cake consists of layers of sponge cake, buttercream and chocolate ganache, topped with a layer of chocolate glaze. We chose to serve our cake sliced, decorated with edible gold paint, but traditionally the cake would be served whole, with the word “Opera” piped on top in chocolate ganache. Either way, it’s a decadent hit of chocolate and coffee goodness best to share with friends so you aren’t tempted to go for a second slice!

Joconde Sponge Cake:

  • 85g   almond meal
  • 75g   icing sugar
  • 25g   plain flour
  • 120g eggs (around 2 medium eggs)
  • 80g   egg whites
  • 10g   caster sugar
  • 30g   butter, melted

Preheat oven to 200°C. Mix together the almonds, icing sugar and flour in a bowl. Add the eggs a little at a time and mix well until the batter becomes smooth and pale. In a separate bowl, whip the egg whites and sugar together until they form stiff peaks. Gently fold the batter into the whipped egg whites, then fold in the melted butter.

Spread the mixture on a baking sheet lined with baking paper to 5mm thickness, smoothing the mixture to ensure an even layer across the baking sheet. Bake for 15 minutes, or until the cake is golden and firm to the touch. Remove form the baking sheet and cool on a wire rack.

Coffee Buttercream:

  • 5g instant coffee
  • 15ml boiling water
  • 250g sugar
  • 60ml water
  • 90g egg yolks
  • 300g butter, softened
  • 4ml vanilla extract
  1. Dissolve the instant coffee in 15ml of boiling water and set aside to cool.
  2. Combine the sugar and 60ml water in a saucepan and place over a medium heat, stirring to dissolve the sugar. Continue to boil until the sugar syrup reaches 115°
  3. While the syrup is boiling, beat the egg yolks until they are thick and pale.
  4. As soon as the syrup reaches 115°C, pour it slowly into the egg yolks, continuing to whisk constantly.
  5. Continue to beat until the mixture has completely cooled. The yolks should be very thick and pale.
  6. Continue beating the mixture as you add the butter a little at a time.
  7. Beat in the vanilla and coffee mixture. If the buttercream is too soft to spread, refrigerate until it becomes firmer.

Dessert Syrup

  • ½ cup sugar
  • ½ cup water
  • 1 tsp instant coffee

Combine sugar and water in a saucepan and bring the boil, stirring until sugar dissolves. Add the coffee and stir well.

Chocolate Ganache

  • 200g dark chocolate, chopped
  • 250g double cream

Melt the chocolate in a bowl set over a hot water bath. Heat the cream and add to the chocolate. Mix well and chill.

Opera Glaze

  • 350g dark chocolate couverture
  • 60g peanut oil

Melt chocolate in a bowl set over a hot water bath. Stir in the oil. Allow to cool a little before using. (Makes a thin coating which sets solid but can easily be cut with a hot knife)

To assemble:

  • Joconde Sponge Cake
  • 50g dark chocolate, melted
  • Dessert Syrup
  • Coffee Buttercream
  • Chocolate Ganache
  • Opera Glaze
  1. Cut the sponge into 3 equal rectangular portions. Spread one piece with a think layer of dark chocolate, then refrigerate to set the chocolate
  2. Remove the chocolate coated sponge from the refrigerator, turn chocolate side down and brush with the Dessert Syrup.
  3. Spread a layer of Coffee Buttercream above the sponge rectangle, about 5mm thick.
  4. Place the second sponge rectangle on top. Brush with the syrup and then spread a thin layer of Chocolate Ganache on top.
  5. Top with the third and final layer of sponge. Brush with the syrup and spread with a layer of Coffee Buttercream, about 5mm thick. Smooth the top carefully with a palette knife.
  6. Refrigerate or freeze until firm. The cake must be quite cold so the warm glaze doesn’t melt the buttercream.
  7. Place the cake on a wire rack over a tray and pour over the warm Opera Glaze. Smooth the surface with a palette knife and refrigerate the cake until the glaze has set.
  8. Remove cake from the rack and trim the sides of the cake with a hot knife.

To Serve:

  • ¼ tsp gold powder
  • ½ tsp gin

If you like, cut the cake into rectangular slices approximately 5cm x 10cm. Mix together the gold powder and gin, and using a fine paintbrush, decorate the top of each slice with a triangle of golden glaze. Use a piece of baking paper cut to purpose as a guide to ensure a uniform triangle on each slice of cake.

Alternatively, using chocolate ganache, you could pipe the word “Opera” onto the top of the entire cake and serve whole.

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