Preheat the oven to 180°C.
Process the nuts, flour, and salt in a food processor until nuts are ground.
Beat egg yolks and sugar for three minutes until pale and creamy.
Fold in the zest, coconut, and processed nut mixture.
Whisk egg whites in a separate bowl until stiff peaks form.
Fold the whisked egg whites lightly into the nut batter using a metal spoon.
Spread the batter into a 23cm springform cake tin.
Bake for 40 minutes until the cake is golden.
Mix icing sugar, lime juice, and zest until smooth and glossy.
Cool the cake in the tin for 10 minutes before transferring to a plate.
Spread icing over the warm cake and serve.