In 10-inch skillet, melt butter over medium-high heat. Add onion and celery; cook, stirring occasionally, until tender.
In large bowl, mix bread cubes, parsley, poultry seasoning, salt and pepper. Add broth and butter-onion mixture, stirring until desired moistness (stuffing will become a little more moist during roasting because it absorbs juices from turkey).
Use to stuff one 14- to 18-pound turkey. After stuffing turkey, place any remaining stuffing in 1- or 2-quart casserole that's been sprayed with cooking spray; cover and refrigerate. Bake stuffing in casserole with turkey for last 35 to 40 minutes of roasting time or until thoroughly heated.