Pierce each tangerine with a clove and place in a large mixing bowl. Pour the Armagnac or eau-de-vie over the tangerines and macerate overnight. In a large saucepan heat the sugar and water over low heat, stirring constantly until the sugar dissolves. Once the mixture is clear, raise the heat and bring to a boil. Simmer for 3 minutes. Remove pan from the heat and stir in the vanilla. Remove the tangerines from the liqueur and discard them. Pour the reserved liqueur into a large sterilized mason jar. Pour the sugar syrup into the mason jar. Cover and seal the jar. Serve the liqueur as an after-dinner drink.
