• 250g chocolate biscuits (not chocolate-coated)
  • 1 tablespoon cocoa powder
  • 120g unsalted butter, melted
  • 500ml (2 cups) full-cream milk
  • 1 vanilla bean, split
  • 6 egg yolks
  • 125g caster sugar
  • 2 teaspoons cornflour
  • 200ml thickened cream
  • Step 1 Place the biscuits and cocoa powder in a food processor and process until the mixture resembles fine crumbs. Add the butter and process to combine. Use the mixture to line a greased 27cm pie dish. Refrigerate.
  • Step 2 Place the milk and the vanilla bean in a saucepan and bring to the boil. Set aside for 30 minutes to infuse. Remove and discard the vanilla bean.
  • Step 3 Beat together the egg yolks, sugar and cornflour in a bowl. Pour the infused milk over the eggs, then return to the saucepan. Cook over low heat for 5-6 minutes, stirring occasionally, until thick. Pour into a bowl. Set aside to cool over iced water.
  • Step 4 Whip the cream and fold into the mixture. Transfer to freezer for 30 minutes until it begins to thicken.
  • Step 5 To make the raspberry sauce, place the sugar and 2 tablespoons water in a small saucepan over medium heat, stirring to dissolve the sugar. Set aside to cool slightly, then add the raspberries and lemon juice. Transfer to a food processor and process until smooth. Pass through a sieve.
  • Step 6 Pour the ice-cream mixture into the pie dish and use a knife to make ridges. Pour some of the sauce into the ridges, then swirl to form a pattern. Freeze overnight.
  • Step 7 Transfer to the fridge for 30 minutes before serving. Serve the pie with the remaining raspberry sauce drizzled over the top.