Vegan Opera Cake with Coconut Butter

Line two 20 cm × 30 cm baking trays with parchment. Preheat the oven to 200°C (180°C fan). In a large bowl, whisk together almond flour, icing sugar, the first 60 ml of aquafaba, and plain flour until a smooth, thick paste forms. Stir in the melted coconut oil.

In a separate clean bowl, beat the second 120 ml of aquafaba with the cream of tartar using an electric mixer on medium-high until soft peaks form. Gradually add the caster sugar, one tablespoon at a time, beating until stiff, glossy peaks form.

Fold one-third of the aquafaba meringue into the almond paste to loosen it, then gently fold in the remaining meringue in two additions until just combined with no white streaks. Divide the batter evenly between the two lined trays and spread into thin, even layers approximately 5 mm thick.

Bake both trays for 8–10 minutes until the joconde is lightly golden, springs back when lightly pressed, and just pulling away from the edges. Remove and cool completely on the trays.

Make the espresso syrup: stir the hot espresso and caster sugar together until the sugar fully dissolves. Set aside to cool.

Make the coconut butter buttercream: beat the softened coconut butter and icing sugar together on medium speed for 3 minutes until pale and fluffy. Add the cooled espresso, vanilla extract, and salt, beating for a further 2 minutes until smooth and spreadable. Refrigerate for 15 minutes to firm slightly.

Make the dark chocolate ganache: place the chopped chocolate and coconut oil in a heatproof bowl. Heat the coconut cream in a small saucepan over medium heat until it just begins to simmer around the edges, then pour over the chocolate. Let stand for 2 minutes, then stir from the centre outward until completely smooth and glossy. Cool to room temperature until spreadable but not liquid.

Make the chocolate glaze: repeat the same process — pour hot simmered coconut cream over chopped chocolate and coconut oil, rest 2 minutes, then stir until smooth. Set aside at room temperature; it should be pourable but thick enough to coat.

Assemble the gâteau: cut each joconde sheet into two equal rectangles approximately 20 cm × 15 cm, giving four layers total. Place the first layer on a flat board lined with parchment. Brush generously with espresso syrup. Spread an even layer of coconut butter buttercream (approximately 4–5 mm thick) across the surface.

Place the second joconde layer on top, press gently, and brush with espresso syrup. Spread an even layer of dark chocolate ganache across the surface.

Place the third joconde layer on top, press gently, brush with espresso syrup, and spread another layer of coconut butter buttercream.

Place the fourth and final joconde layer on top, press gently, and brush with espresso syrup. Refrigerate the assembled cake uncovered for 30 minutes until the layers are set and firm.

Pour the chocolate glaze over the top of the chilled gâteau and use a palette knife in one smooth, confident pass to spread it into a perfectly level, glossy mirror layer. Refrigerate uncovered for a further 60 minutes until the glaze is fully set.

Trim all four sides of the cake with a sharp knife warmed in hot water and wiped dry between each cut to reveal clean, defined layers. Slice into portions and serve at cool room temperature.