When I was a teenager a friend had this cake as her birthday cake and I became obsessed with finding a recipe for it!
The fêted Parisian chef Gaston Lenôtre designed menus for Air France and created this dessert as a tribute to the inaugural flight of legendary Concorde aircraft in the 1969. The gâteau is a combination of layers of chocolate meringue and chocolate mousse. Florence Fabricant, a writer for the New York Times describes it as "the ultimate dacquoise, mousse layered with crisp meringue collapsing into a creamy pillow at the touch of a fork."
Edd Kimber, the inaugural winner of the Great British Bake-Off has produced a magnificent version of the cake.
6 large egg whites
60 g caster sugar
300 g icing sugar
30 g cocoa powder
icing sugar or cocoa powder, for dusting
For the chocolate mousse
185g dark chocolate (around 70%), finely chopped
500ml double cream
Preheat the oven to 120°C and line three baking sheets with baking parchment. Using a 20cm cake tin as a template, draw a circle on each piece of parchment, then turn it over so that the drawing is underneath.
Put the egg whites into a clean, grease-free bowl and, using an electric mixer, whisk until they form stiff peaks. Slowly pour in the caster sugar and whisk until the meringue is stiff and glossy. Sift the icing sugar and cocoa powder over the meringue and gently fold together, being as gentle as possible.
Spoon the meringue into a piping bag fitted with a 1cm wide plain piping tip and pipe three discs on the baking parchment using the drawn templates, piping in a spiral starting at the centre and working outwards. Using the remaining meringue, pipe long strips onto the prepared trays alongside the discs (keep some space between them as they will expand a little in the oven. Bake for about 1 hour 40 minutes or until firm and crisp. Turn off the oven and allow the meringues to cool in the oven for 2 hours.
To make the mousse, melt the chocolate in a large heatproof bowl set over a pan of gently simmering water, making sure the base of the bowl doesn’t touch the water.
Remove from the heat and leave to cool. Whisk the cream to soft peaks then pour it into the bowl with the chocolate and whisk to combine. The resulting mousse should be fairly thick and be able to hold its shape, but not so thick it can’t be spread easily. If it is too thick and looks overwhipped, pour in a little extra cream or milk and stir to loosen the mousse.
To assemble the cake, use a little of the mousse to stick the first meringue disc to a cardboard cake board or serving plate. Spread about a third of the mousse over the meringue and then add another meringue and repeat the process. Top with the final meringue and then coat the top and sides of the cake with the remaining third of the mousse.
To finish the decoration, use a serrated knife to very gently cut the meringue strips into pieces. Lightly press these all over the cake and lightly dust with either icing sugar or cocoa powder. You can either serve the cake now or you can freeze it for a few hours; this will soften the meringue slightly. If you do freeze the cake, thaw it in the fridge for a few hours before serving.