Freeze your ice cream bowl for at least 12 hours before starting.
In a saucepan, combine the milk, caster sugar and salt. Place over medium heat and stir until the sugar has fully dissolved and the mixture is hot (but not boiling).
Remove from the heat and whisk in the pistachio spread until smooth and fully incorporated. You may find it easier to use a blender for this step.
Stir through the thickened cream and vanilla extract until well combined. Transfer the mixture to a container and refrigerate for at least 4 hours, or ideally overnight.
Pour the chilled mixture into your ice cream maker and churn for 15-20 minutes, or until it reaches a thick, soft-serve consistency.
Transfer to an airtight container, then dollop over small spoonfuls of extra pistachio spread and sprinkle with the chopped pistachios. Freeze for another 2-3 hours before serving in cones or bowls.
