he amount of pistachios I’ve used here is a bit extravagant, but the cake goes quite a long way and is a really great special-occasion number, so it’s worth it. Like all cakes full of ground nuts, it’s lovely and moist, plus the uniced cake keeps well.
Grease and line an 8 cup (2 litre) capacity, 13 x 24 cm (5 x 9½ inch) loaf tin with baking paper.
Spread the pistachios and almonds over a shallow baking tray and roast for about 10 minutes or until they are just becoming aromatic.
Set the nuts aside to cool for a few minutes, then tip them into a food processor and blitz for about 5 seconds or until rough crumbs form.
Remove and reserve 2 tablespoons of the crumbs, then process the remaining crumbs until you have a fine meal.
Add the flour, baking powder, salt and cinnamon and blitz for a few seconds to combine.
Beat the butter, sugar and lemon zest in an electric mixer fitted with the paddle attachment (or use a mixing bowl and wooden spoon) until pale and fluffy.
Add the eggs, one at a time, beating well after each addition.
Fold in the nut and flour mixture and the lemon juice, then gently spoon the batter into the tin.
Bake the cake for about 45 minutes or until it is pulling away from the sides of the tin and a skewer inserted in the middle comes out clean.
Leave the cake to cool in the tin for 5 minutes, then turn it out onto a wire rack to cool completely.
For the icing, mix the icing sugar, lemon zest and lemon juice in a bowl until smooth and thick.
Pour the icing over the cooled cake and let it set for a few minutes, then sprinkle the reserved nut crumbs over the top.