Gateau Diane

Serves: 12
Course: Dessert
  • For the chocolate-cream filling:
  • 400ml cream
  • 250g 55%-cocoa dark chocolate, chopped
  • Chocolate meringue
  • 6 large egg whites
  • 300g caster sugar
  • 1tbsp cornflour
  • 1tbsp good quality cocoa powder (plus extra for dusting the top)
  • For the sweetened vanilla cream:
  • 350ml fresh cream (or whipped cream)
  • 2tbsp icing sugar
  • 1 vanilla pod (split lengthways, seeds removed)
  • To decorate:
  • 25g finely grated dark chocolate

For the chocolate cream filling: Prepare the chocolate cream at least 4 hours in advance of assembling the gateau. Put the fresh cream into a saucepan and bring just barely to the boil. Pour it over the chopped chocolate in a bowl, leave to sit for 1 minute before stirring until the chocolate is glossy and smooth. Set aside, stirring until the mixture is no longer warm to the touch (you can place it in the fridge to help cool it down, but remove it before it stiffens up).

When ready to whip, use an electric whisk to whip the chocolate cream to a thick mousse-like consistency, firm enough to sit between layers.

For the chocolate meringue layers: Preheat the oven to 120°C fan. Use three 26x16cm baking tins, grease and line each with baking parchment (alternatively use a pencil to clearly draw three same size rectangles on the reverse of parchment paper placed on a baking sheet).

In a large mixing bowl, use an electric handheld whisk to beat the egg whites to soft peaks. Gradually add the caster sugar and continue whisking until the mixture is stiff and glossy. Sieve together the cocoa powder and cornflour and gently fold into the meringue mixture.

Spoon the meringue into a large piping bag. Neatly pipe a third in three baking trays (alternatively, pipe the outline of 3 rectangles and spread filling inside). Bake for 1½ hours until crisp and dried out.

Whip the cream lightly then beat in the icing sugar and vanilla seeds from the vanilla pod.

To assemble the layered gateau: Fill the gateau at least 2-3 hours before serving. On top of the first layer of meringue, spread half the chocolate cream. Next spread freshly whipped cream over the chocolate filling. Repeat with the second meringue layer. Place the third meringue on top and finish with a light dusting of cocoa powder. Decorate with grated chocolate.

For a variation, add your own signature to this dessert with a dash of liqueur such as Baileys or Tia Maria added to the chocolate cream. For a nutty flavour, fold ground almonds through the meringue mixture or for extra crunchiness, scatter toasted flaked almonds between layers.