Wash the cherries and trim the stems. Leave about 1/2 inch of the stems.
Put the cherries in a 1 quart canning jar and fill with the rum to completely cover the cherries. Add the vanilla extract, close the jar and store in a cool dry location of the house.
You can start enjoying the cherries after about one month but they are better if served during the holidays as a special treat.
By then the rum will have become a deliciuos cherry liqueur.