Preparation Stir together all ingredients in a heavy medium saucepan until sugar has dissolved. Bring to a boil, then simmer, uncovered, gently stirring occasionally, until liquid is reduced by half, about 25 minutes. Remove from heat and cool until barely warm or room temperature. Discard vanilla bean. Cooks' note:Prunes can be cooked 3 days ahead and chilled, covered. Bring to room temperature before serving.
Preparation Stir together all ingredients in a heavy medium saucepan until sugar has dissolved. Bring to a boil, then simmer, uncovered, gently stirring occasionally, until liquid is reduced by half, about 25 minutes. Remove from heat and cool until barely warm or room temperature. Discard vanilla bean. Cooks' note:Prunes can be cooked 3 days ahead and chilled, covered. Bring to room temperature before serving.