The classic seven-layer coffee-chocolate entremets: three joconde sheets soaked in coffee syrup, coffee French buttercream, dark ganache, chocolate glaze. Built in a 34 × 24 cm frame, 2.5 cm tall, cut 24 slices. Every layer must be dead level — the Opéra is judged on its cross-section. Holds 3 days at 2-4°C; cut with a hot dry knife.
Yield: 24 portions · Prep 180 min · Bake 30 min
Ingredients
225 g almond flour (joconde)
225 g icing sugar (joconde)
300 g whole egg (joconde)
200 g egg white (joconde)
30 g caster sugar (joconde)
60 g plain flour (joconde)
45 g unsalted butter (joconde, melted)
300 ml water (coffee syrup)
150 g caster sugar (coffee syrup)
15 g instant coffee (syrup)
300 g unsalted butter (buttercream)
180 g caster sugar (buttercream syrup)
60 ml water (buttercream syrup)
100 g egg yolk (buttercream)
15 ml coffee extract
200 g dark chocolate 64% (ganache)
200 ml cream 35% (ganache)
200 g dark couverture (glaze)
30 ml neutral oil (glaze)
Method
Joconde sheets Make joconde per the foundation recipe and spread 3 sheets at ~5 mm on lined trays. Bake at 220°C for 8-10 minutes until light gold and springy. Cool on racks; trim each to 34 × 24 cm.
Coffee syrup Boil water and sugar, dissolve the instant coffee, and cool. The syrup is applied generously — an Opéra reads dry if the joconde is under-soaked; budget all of it across the three sheets.
Coffee French buttercream Cook sugar and water to 118°C and stream onto whipping yolks (pâte à bombe); whisk to cool, then beat in soft butter cube by cube and flavour with coffee extract. The buttercream must be smooth, light, and at 18-20°C for spreading.
Ganache Bring the cream to a simmer and pour over the chopped 64% chocolate; rest 1 minute, stir from the centre, and cool to a spreadable 30-32°C.
Montage In the frame: sealed joconde (thin coat of melted couverture on the base sheet), syrup, half the buttercream; joconde, syrup, all the ganache; joconde, syrup, remaining buttercream, levelled with an offset spatula against the frame edge. Freeze 30 minutes between layers if the room is warm.
Glaze and cut Melt couverture with the oil to 35°C and pour over the chilled slab in one pass, spreading with as few strokes as possible. Set 10 minutes, deframe with a hot knife, trim the edges to expose the layers, and portion 24 slices with a hot dry blade, wiping between every cut.