Preheat the oven to 350°F. Spray a baking dish with cooking spray (I use a 2-quart baking dish).
Cut the bread into ½-inch cubes; place in a large bowl.
In a large skillet, melt the butter. Add the celery and onions and sauté until tender, about 10 minutes.
Add the poultry seasoning and salt and pepper to the celery and onion mixture. Stir to combine.
Add the celery and onion mixture to the bread cubes; stir well to combine.
Add the chicken broth; stir gently to combine. Note: The 1½ to 2 cups of broth gives me the amount of moisture I like for my stuffing - moist but not overly wet. The first time you make this, you may not want to add all the broth all at once but instead add it a bit at a time until the stuffing is how you like it. You may even want to add more broth. Just be careful not to add too much so that the stuffing doesn't become mushy.
Taste and adjust seasoning, if needed.
Spoon the stuffing mixture into the prepared baking dish. Bake, uncovered, for 40 minutes or until heated through and lightly golden brown and crisp on top.