A classic French entremet of almond joconde sponge, coffee syrup, coffee French buttercream, dark chocolate ganache, and a glossy chocolate glaze.
Ingredients
Joconde almond sponge (3 thin sheets, 30×40 cm each)
250 g almond flour
250 g powdered sugar
250 g whole eggs (about 5 large), room temperature
60 g cake flour
50 g unsalted butter, melted and cooled
175 g egg whites (about 5 large), room temperature
50 g granulated sugar
2 g fine salt
Coffee syrup
200 ml water
150 g granulated sugar
150 ml strong espresso, cooled
30 ml coffee liqueur (optional)
Coffee French buttercream
150 g egg yolks (about 8 large), room temperature
200 g granulated sugar
60 ml water
400 g unsalted butter, very soft
30 ml concentrated espresso, cooled
5 ml coffee extract
2 g fine salt
Dark chocolate ganache layer
300 g dark chocolate 66–70%, finely chopped
300 ml heavy cream 35%
40 g glucose syrup or light corn syrup
30 g unsalted butter, room temperature
Chocolate glaze
200 g dark chocolate 66–70%, finely chopped
30 g unsalted butter
20 ml neutral oil (grapeseed or sunflower)
To finish (optional)
20 g melted dark chocolate for piping “Opera”
Steps
Preheat the oven to 220°C conventional.
Line a 30×40 cm rimmed sheet pan with parchment paper.
Grease the parchment lightly.
Melt the butter for the sponge and cool it.
Combine almond flour, powdered sugar, and whole eggs in a mixing bowl.
Whisk the almond mixture until pale and thick.
Sift the cake flour over the almond mixture.
Fold the flour into the almond mixture.
Combine egg whites, granulated sugar, and salt in a clean bowl.
Whip the egg white mixture to medium peaks.
Fold half of the meringue into the almond mixture.
Fold the remaining meringue into the almond mixture.
Fold the cooled melted butter into the batter.
Weigh the batter and divide it into 3 equal portions.
Spread one portion evenly in the prepared pan to a thin, even layer.
Bake the sponge for 7–9 minutes until light golden at the edges.
Slide the sponge on its parchment to a rack and cool it.
Reline the pan with fresh parchment.
Spread the second portion of batter evenly in the pan.
Bake the second sponge for 7–9 minutes until set and lightly colored.
Slide the sponge on its parchment to a rack and cool it.
Reline the pan with fresh parchment.
Spread the third portion of batter evenly in the pan.
Bake the third sponge for 7–9 minutes until set and lightly colored.
Slide the sponge on its parchment to a rack and cool it.
Combine water and sugar for the syrup in a saucepan.
Boil the syrup until the sugar dissolves.
Remove the syrup from the heat.
Stir in the espresso.
Stir in the coffee liqueur.
Cool the syrup to room temperature.
Combine granulated sugar and water for the buttercream in a small saucepan.
Boil the syrup to 118°C.
Place the egg yolks in a stand mixer bowl.
Whisk the yolks on medium speed until thick and pale.
Pour the hot syrup into the yolks in a thin stream.
Whip the mixture on medium-high speed until it reaches room temperature.
Beat the soft butter into the yolk mixture until smooth.
Beat in the espresso, coffee extract, and salt until homogeneous.
Chill the buttercream for 10–15 minutes until just spreadable.
Heat the cream and glucose for the ganache in a saucepan until steaming.
Pour the hot cream over the chopped chocolate.
Rest the mixture for 2 minutes.
Stir the ganache from the center until emulsified and smooth.
Stir the butter into the ganache until glossy.
Cool the ganache to 30–32°C.
Trim each sponge to 22×30 cm to square the edges.
Place a 22×30 cm cake frame or adjustable entremet frame on a parchment-lined tray.
Place one sponge inside the frame.
Brush the sponge evenly with coffee syrup to moisten it.
Spread half of the buttercream over the sponge in a thin, even layer.
Level the buttercream with an offset spatula.
Place the second sponge over the buttercream.
Brush the second sponge evenly with coffee syrup.
Spread all of the ganache over the second sponge in a smooth layer.
Refrigerate the tray for 20–30 minutes until the ganache is firm.
Place the third sponge over the ganache.
Brush the third sponge evenly with coffee syrup.
Spread the remaining buttercream over the top in a thin, even layer.
Smooth the surface carefully to a flat finish.
Freeze the cake for 15 minutes to set the surface.
Melt the chocolate and butter for the glaze gently over a bain-marie.
Stir the neutral oil into the melted chocolate mixture.
Cool the glaze to 32°C.
Pour the glaze over the cake to cover the surface in a thin layer.
Tilt the tray to level the glaze.
Refrigerate the cake for 30–45 minutes until the glaze sets.
Warm a long knife under hot water and dry it.
Trim 2–3 mm from all edges for clean sides.
Pipe “Opera” on the surface with melted chocolate if desired.
Cut the cake into 12 neat rectangles.
Refrigerate the slices until serving.
Notes
Provenance: Opera cake is a Parisian classic popularized by Dalloyau in the mid-20th century, known for thin, even layers and a glossy finish.
Joconde tips: Spread the batter very thinly and bake just until set to keep it flexible and moist; overbaking will crack the layers.
Syruping: Moisten generously but avoid saturating; aim for an evenly damp crumb without pooling.
Buttercream: For best texture, ensure the pâte à bombe (yolks plus syrup) cools to room temperature before adding butter; if it curdles, continue beating until smooth.
Ganache: Target 30–32°C for spreading to prevent melting the buttercream or setting too firm to level.
Glaze: Pour at about 32°C for a thin, shiny coat that still cuts cleanly; warm the knife and wipe between cuts for sharp edges.
Make-ahead: Assemble up to the glazing step a day in advance and keep refrigerated; glaze on the day for best shine.
Variations: Substitute hazelnut flour for almond in the joconde; swap coffee liqueur with dark rum; add a thin layer of tempered chocolate under the first sponge for extra crunch (traditionally called a “feuilletine” insert).
Related techniques: See also Joconde Sponge, French Buttercream, and Pouring Chocolate Glaze for deeper technique guidance.
Cooksmith