To shell the nuts
Line the cake tin with baking paper. Spread the nuts on a baking tray.
Roast for approx. 8 mins. in the centre of an oven preheated to 200 °C until the shells crack open. Remove, allow the nuts to cool slightly. Rub the nuts gently with a damp towel until all the shells have been removed.
Place the butter in a bowl, add the sugar and salt, beat together. Add the egg yolks, continue to beat using the whisk on a mixer until the mixture becomes lighter in colour.
Roughly chop the chocolate, mix with the toasted and ground nuts, flour and baking powder, add, mix well. Beat the egg whites with the salt until stiff, carefully fold into the mixture using a rubber spatula.
Transfer the cake batter to the prepared tin.
Approx. 50 mins. in the lower half of an oven preheated to 180°C. Remove the cake from the oven, allow to cool slightly, remove from the tin and leave to cool on a rack.