200g/7oz plain flour
75驳/2戮辞锄 caster sugar, plus an extra 40g/1陆oz for the topping
50g/1戮oz blanched hazelnuts
150g/5陆oz unsalted butter, cubed and cold
500ml/18fl oz double cream
9 egg yolks (save some egg white to glaze)
50g/1戮oz salted pretzels