Opera cake

Method

Make the almond sponge (joconde) by whisking 4 eggs with 120g caster sugar over gentle heat until 40°C, then whisk to ribbon stage off heat; fold in 40g flour and 20g cocoa sifted together, then fold in 40g melted butter. Spread 3mm thick on two 20cm square baking trays lined with baking parchment and bake at 200°C (180°C fan) for 12-14 minutes until springy; cool completely. Prepare the espresso syrup by dissolving 5g espresso powder in 60ml boiling water with 30g caster sugar; cool. Make the chocolate coffee buttercream by beating 200g soft butter until pale, then beating in 150g melted dark chocolate and 60ml cooled coffee, alternating in three additions; fold in 200ml softly whipped cream and 40g icing sugar. Assemble: place one sponge on a lined tray, brush with espresso syrup, spread with half the buttercream. Top with second sponge, brush with syrup, spread remaining buttercream. Chill 2 hours until firm. Prepare the ganache by heating 150ml cream to steam, pouring over 200g chopped dark chocolate with 3g espresso powder, resting 1 minute, then stirring until glossy. Cool to 32°C, spread over opera cake, chill 1 hour. Trim edges cleanly with a hot knife, cut into 12 rectangles and serve chilled.