200g/7oz plain flour
75²µ/2¾´Ç³ú caster sugar, plus an extra 40g/1½oz for the topping
50g/1¾oz blanched hazelnuts
150g/5½oz unsalted butter, cubed and cold
500ml/18fl oz double cream
9 egg yolks (save some egg white to glaze)
50g/1¾oz salted pretzels