1 lemon, zest only
50g/1戮oz fresh raspberries
35驳/1录辞锄 plain flour
60g/2录 oz ground almonds
115g/4oz icing sugar, sifted, plus extra to serve
2 tbsp shelled pistachios, roughly chopped
pinch salt
115g/4oz butter, cubed, plus extra for greasing
3 free-range egg whites