Sigh Cake with Chestnut and Chocolate Mousse

Make the sigh component

In a mixer, beat the egg whites until stiff peaks form

Add the sugar gradually, beating continuously, until firm peaks form

Add the ground chestnuts and mix gently

Distribute among three 23 cm diameter molds, with the bottoms lined with parchment paper, greased with oil (including the sides)

Dust with wheat flour

Bake in a moderate oven (180°C), preheated, for 20 minutes or until firm

Let cool, then unmold carefully, remove the parchment paper and reserve

Make the mousse

Melt the chocolate in a double boiler

Remove from heat, add the butter, egg yolk, coffee and mix

In a mixer, beat the egg whites until stiff peaks form

Add the sugar gradually, beating continuously, until firm peaks form

Add the chocolate mixture and mix

Cover with plastic wrap and refrigerate for 40 minutes or until set

Divide the mousse into three portions

Alternate the cake disks with layers of mousse in a serving dish

Refrigerate for at least one hour before serving, garnished with chocolate and chestnut shavings