Heat blueberries, caster sugar and water together in a small saucepan until simmering. Cook until the blueberries have broken down somewhat. Remove from heat and puree. Set aside to cool.

Add the double cream and milk to a small blender with the whip attachment, and whip until thick. Alternatively, whisk with a hand whisk and elbow power.

Stir in the cooled blueberry mixture, the vanilla and the vodka if using.

Spoon into four ice lolly moulds and freeze for half an hour before inserting wooden lolly sticks. Freeze until solid.

Break the white chocolate into pieces and place into a small heatproof bowl along with the coconut oil. Suspend over a pan of barely simmering water until melted. Allow to cool to room temperature.

Loosen the ice cream lollies from the moulds by running under cool water.

Dip the ends of the creamy blueberry ice lollies into the white chocolate mixture and transfer to a silicone mat or piece of greaseproof paper. Decorate with the sprinkles before the chocolate sets.

These ice cream lollies will keep for up to a week in the freezer in a freezerproof container.