Fragilité cake with blueberry and raspberry mousse

Pre-heat the oven to 150°C.

Roast the hazelnuts in a large dry frying pan. Tip them onto a tea towel and rub off as much of the skin as possible. Chop the hazelnuts with a blender while adding the brown sugar in a stream. Put to one side.

In a bowl whisk the egg whites until stiff. Then add the sugar a little at a time while continuing to whisk. Fold the hazelnut and brown sugar mixture into the meringue.

Spread two thirds of the mixture in a thin layer on a parchment-lined baking sheet, 40x30 cm. Draw a rectangle, 20x30 cm, on a new piece of parchment paper and place on a baking sheet. Spread the rest of the mixture on this.

Bake one sheet at a time in the bottom of the oven for about 15-20 minutes. Leave the bases to cool.

Meanwhile, prepare the mousse. Boil the berries together with 1 dl water for about 5 minutes. Add the sugar and boil the mixture for another 5 minutes.

Mix the corn starch with 1-2 tsp water and stir into the berry compote. Leave to boil for 2-3 minutes. Remove the pan from the heat and leave to cool completely.

Whisk the cream until fluffy and fold into the berry compote.

Cut the large hazelnut base in two. Place one of the bases on a plate and spread over half of the mousse. Place the next base on top. Spread over a new layer of mousse and place the third base on top.