- 5 eggs, separated
- 275g (9 oz) caster sugar
- 3 tbsp cocoa
- 200g (6½ oz) dark chocolate
- 1 tbsp instant coffee powder
- 600 ml (20 fl oz) double cream, whipped
- Heat the oven to 150°C (gas mark 2). Line four baking sheets with non-stick greaseproof paper. Mark 22 cm (9 in) circles on three trays.
- Using a clean, dry bowl, whisk the egg whites with an electric mixer until stiff. Gradually add the sugar, beating constantly after each addition. Beat for 5-10 minutes - the mixture should be thick and glossy. Sift in the cocoa and gently fold in with a large metal spoon.
- Divide the mixture into four portions and spread three portions over the circles. Transfer the remaining mixture into a piping bag fitted with a large plain piping nozzle and pipe 3-4 rows over the baking paper.
- Bake for 50 minutes or until pale and crisp, in two batches if your oven isn't big enough. Turn off the oven, open the door and leave the meringues to cool completely inside.
- Make the filling by melting the chocolate in a large heatproof bowl over a saucepan of very hot water. Allow to cool slightly and then gradually whisk in the egg yolks and the coffee (dissolved in 1 tbsp of water). Beat until smooth. Fold in the whipped cream and mix until combined. Chill for at least 3 hours, or until ready to assemble the cake.
- To assemble, place one circle of meringue on a round serving plate and spread with one third of the chilled mousse. Repeat with the other two layers, finishing with a layer of mousse.
- Break the meringue sticks into lengths and pile them on top of the cake. Dust with a little cocoa.
You can make the meringue and mousse ahead of time and assemble at the last minute. Sprinkle with edible decorations.