In sterilized quart screw top jar, mix vodka, sugar and the split vanilla beans. Cover tightly and shake jar until sugar dissolves. Allow mixture to stand (steep) in a cool dark place for 1 month. Remove vanilla beans; discard. Transfer liqueur to clean decorative bottles with tight fitting lids. If desired, add a vanilla bean to each bottle for garnish. Seal and label. Store at room temperature. Makes 2 1/2 cups of liqueur.