Opéra

Preparation

Step 1: Make the joconde sponge

Preheat the oven to 200 °C (convection).

In a bowl, mix almond flour, sifted powdered sugar and flour. Add whole eggs one at a time, whisking. Stir in the melted butter. Mix until smooth.

Whip the egg whites with the caster sugar until firm and glossy. Gently fold into the almond mixture.

Spread the batter onto a parchment-lined baking tray (30×40 cm) to 1 cm thickness. Bake for 10-12 minutes. The sponge should be lightly golden and springy to the touch.

Turn out onto a cooling rack and let cool.

Step 2: Make the coffee syrup

Dissolve the sugar in boiling water. Add the very strong black coffee. Let cool completely.

Step 3: Make the chocolate ganache

Heat the cream until simmering. Pour it in three batches over the chopped dark chocolate, stirring from the centre outward in concentric circles to create an emulsion. Add the softened butter and mix until smooth and shiny.

Let cool to room temperature (it should be still soft, not set).

Step 4: Make the coffee buttercream

Make a syrup with the sugar and water: heat to 118 °C on a thermometer.

Meanwhile, whisk the egg yolks with an electric mixer. Pour the hot syrup in a steady stream over the yolks while whisking continuously. Whisk until completely cool (the mixture should become pale and frothy).

Add the softened butter little by little, whisking. Incorporate the very strong coffee. Whisk until smooth and homogeneous.

Step 5: Assemble the cake

Cut the joconde sponge into 4 rectangles of 10×20 cm.

Place one sponge rectangle in the bottom of an entremets frame (or on the serving dish). Generously brush with coffee syrup.

Spread a layer of coffee buttercream (about one third) over the entire surface.

Place a second sponge rectangle, brush with syrup, and spread half of the chocolate ganache.

Place a third rectangle, brush with syrup, and spread the second third of the buttercream.

Finish with the fourth rectangle, brush with syrup. Refrigerate for at least 2 hours.

Step 6: Glaze

Prepare the glaze: melt the dark chocolate with the cocoa butter (or white chocolate) in a bain-marie to 35 °C.

Remove the cake from the fridge. Pour the glaze over the top and spread quickly with an offset spatula for a smooth, even surface.

Return to the fridge for 30 minutes to set the glaze.

Step 7: Finish and serve

Trim the edges of the cake with a large serrated knife to reveal clean layers.

Cut into individual rectangles (about 3×6 cm).

Decorate each piece with a gold motif or a chocolate coffee bean.

Serve at room temperature for all the textures to express themselves fully.