1. Cut off the tops of the persimmons and scoop out the pulp without breaking the skins.
2. Put the pulp into a bowl with the Grappa and let the fruit marinate.
3. In the meantime, put the persimmon shells and tops in the freezer.
4. After an hour, mash the pulp to a fine paste, mix with the vanilla ice-cream, and fill the empty persimmon shells.
5. Cover them with the tops and freeze for about an hour before serving.