Chop rhubarb, top with brown sugar and toss. Let rhubarb sit while gathering the rest of the ingredients. Cube bread and place in 8X8 baking dish. Combine eggs and vanilla, half and half, cinnamon, and salt.
Drain syrup from rhubarb and reserve. Add rhubarb and cranberries to the bread and toss. Stir in sugar syrup to egg mixture. Press bread down with a spoon to make sure the bread is fully saturated. Cover and refrigerate mixture for 2 hours or overnight. Bake the bread pudding at 350 degrees for 40=45 minutes or until set and light golden brown.