Wash plums and pat dry. Cut plums in half or smaller, pit. Place plums in aging container. Pour sugar over plums, stir. Add vodka and brandy stirring to partly dissolve sugar. Cap container and place in a cool, dark place for 2 months, stir occasionally. Place a strainer over large bowl and strain liqueur. Press liquid from plums with the back of a wooden spoon. Discard plum pulp. Re-strain liqueur through cloth until clear. Bottle as desired. Ready for drinking or cooking but best if aged another month.
Serve in a Collins Glass