Simply follow our simply laid out recipe:
1) Preheat the oven to 190°C/375°F/Gas 5.
2) Prepare a 23cm cake tin by lining it with grease proof paper and greasing the sides.
3) Chop the chocolate and place in a bowl set over a pan of gently simmering water to melt.
4) Separate the egg whites from the egg yolks.
5) Once the chocolate has melted, remove it from the heat and beat the butter into the chocolate, bit by bit, until all the butter is incorporated.
6) Add the sugar to the bowl with the egg yolks and whisk together until pale, thick and fluffy.
7) Stir the chocolate mixture into the egg yolk mixture with a metal spoon. Add the ground hazelnuts and the flour to the mixture and gently fold in then add 3 tbsp of the orange liqueur.
8) Using an electric whisk, whisk the egg whites with the salt until stiff peaks form
9) Gently fold the egg whites into the cake mixture with a metal spoon.
10) Pour the cake mixture into the prepared tin and bake for 40-50 minutes, until firm to the touch.
11) When the cake is cooked, remove and cool for 5-10 minutes, then turn out onto a cake rack to finish cooling.
12)Sprinkle with some icing sugar (optional) and serve with some freshly whipped cream.