Method

• 1.
  For the mousse, pour 1 cup (250ml) cream into a saucepan, sprinkle with cinnamon and place over medium heat. Allow cream to heat until just below boiling point, then remove from heat and stand for 10 minutes. Strain into a clean pan through a fine sieve. Stir in chocolate until melted (briefly put the pan over very low heat if necessary), then cool to room temperature. Whip remaining cream well until soft peaks form, then fold it through chocolate mixture. Cover and refrigerate for 2 hours or until firm enough to spread.
• 2.
  Preheat the oven to 140°C and line 3 Swiss roll pans or baking trays with baking paper.
• 3.
  Beat eggwhites using electric beaters until soft peaks form. With motor running, gradually add caster sugar and vanilla extract and beat until stiff peaks form. Combine icing sugar, plain flour and ground hazelnuts in a small bowl, then fold in two large spoonfuls of the meringue until well combined. Gently fold the nut mixture back into the rest of the meringue until well combined, being careful not to beat out the air.

• 4.
  Spoon one third of the mixture into the centre of each baking pan, then smooth out into a rectangle about 18cm x 25cm. Bake for 1 hour or until dry on top. Remove from oven, allow to cool in pans. Turn meringues out and carefully peel off baking paper.
• 5.
  Put one meringue layer on a serving platter, then spread with half the mousse (if mousse has become too firm, whisk with a fork until it softens again).
• 6.
  Top with another meringue layer and spread with remaining mousse. Top with remaining meringue, then cover with plastic wrap and refrigerate for at least a few hours or overnight. The meringue will soften slightly, making the cake easier to slice.
• 7.
  When ready to serve, sift topping ingredients into a bowl, then sift mixture again over cake. If serving the cake whole, you might like to trim the edges. Otherwise, serve cut into neat squares, with lightly whipped cream if desired.