Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray.
In 10-inch nonstick skillet, cook onions and celery over medium-high heat 6 to 8 minutes, stirring occasionally, until onions are golden and tender. Add 3 cups of the broth, the sage, salt and pepper. Heat to boiling. Remove from heat.
In large bowl, toss cranberries and bread cubes. Stir in onion mixture, tossing to evenly coat bread cubes. If desired, add up to 1/2 cup additional broth for a moister dressing.
Spoon dressing into baking dish. Cover with foil. Bake 15 minutes; stir. Recover; bake 20 to 25 minutes longer or until hot in center (165°F).