Unwrap the toffees and put in a plastic food bag and smash with a rolling pin to break them into small pieces. Tip the toffee shards into the sterilised jar, then add the sugar and a pinch of sea salt.

Pour the vodka over the toffee mixture and stir. Leave in a cool dark place for two days or until the toffees have dissolved. Shake the jar twice a day during this time.

Once the toffee and sugar has dissolved, line a funnel with a coffee filter paper and set it over the sterilised bottle. Slowly pour the mixture through. Seal and store in a cupboard for up to three months, and shake before serving.