Begin by making the caramel. Put 1 cup of sugar in a heavy saucepan over very low heat. Swirl it around every minute or so until it turns light brown. Begin stirring as the sugar starts liquefying. Once the lumps are gone, stir vigorously (do not leave it or it will boil over and burn!) for another two minutes. The color should be a rich brown.
Remove the pan from the heat and carefully add ⅓ cup of warm water. The caramel will sputter and steam as it hardens. Return the pan to very low heat, stirring constantly, until caramel is liquid again. Add the pears to the pan and stir constantly, cooking until soft, about 3-4 minutes.
Take off the stove and use a slotted spoon to remove the pears, allowing the caramel to drip back off into the pan. Puree the pears in a food processor or blender until relatively smooth. Set aside.
Put the half-cup of sugar, cream, milk and vanilla scrapings/pod in a medium saucepan and heat over medium until sugar is dissolved and the mixture is warm. Fish out the vanilla pod and discard. Using an electric mixer, whip the cream mixture for several minutes until the mixture thickens and you notice an increase in volume.
Fold in the pureed pears and half of the slightly cooled caramel. Pour the mixture into your ice cream machine and freeze according to manufacturer’s directions. Just before removing the ice cream from the machine, drizzle in the remaining caramel and allow it to mix in slightly for about 30 seconds.
Put ice cream in an airtight container and place in your refrigerator freezer until firm.