Preheat the oven to 325°F.

In a large skillet, melt 6 tablespoons butter and sauté the onions, celery, and mushrooms until just tender, about 5 minutes. Add broth, parsley, sage, salt, and poultry seasoning. Mix well. Place stuffing cubes in a large bowl. Add mushroom mixture and raisins and toss to coat. Stir in just enough warm water to reach desired moistness.

Loosely stuff the turkey. Place any remaining stuffing in a greased baking dish, then cover with foil and refrigerate until ready to bake. Tie drumsticks together with kitchen string. Place turkey, breast side up, on a rack in a roasting pan. Melt remaining 2 tablespoons butter and brush skin of turkey generously with it. Season skin with additional salt and pepper.

Bake turkey, uncovered, for 3 hours 45 minutes to 4 hours or until thermometer reads 175°F for turkey and 165°F for stuffing. Baste occasionally with pan drippings. Cover turkey loosely with foil if browning too quickly. When finished, cover turkey with foil and let stand 20 minutes before removing stuffing and carving.

Bake additional stuffing in pan, covered, for 30-40 minutes. Uncover and bake 10 minutes longer or until lightly browned.