For the cherry sauce, bring all ingredients to a boil in a medium saucepan. Reduce heat to medium low and simmer until cherries start to soften and release juices.
Transfer cherries to a heatproof bowl and set aside. Remove half of the cherries and when cool enough puree them in a blender or processor, then put back in the bowl.
Simmer the remaining juices until it thickens. Pour over cherries, and let cool. For brownies, stir together dry ingredients and wet ingredients in separate bowls.