Put the cherries at the bottom of a sealable glass jar and 2 T reserved liquid from the cans. Add the brandy, vodka (and cinnamon stick, if using) to the cherries. Seal and shake the jar. Let steep for one week at room temperature away from direct sun, shaking every few days.
Combine the reserved cherry liquid from the cans, sugar, and water in a pan and bring to a boil, stirring frequently until sugar dissolves. Remove from heat and let cool. Once the syrup is cooled, add it to the steeping jar, seal, and shake. Then let it steep for an additional 2 to 5 days.
Strain through fine-mesh sieve lined with cheesecloth into glass jar or bottle or leave the cherries for an unfiltered effect. .