Lightly spray the liner of the slow cooker with cooking spray.
In a large skillet over medium heat, melt the butter.
Add the chopped celery and onions to the skillet and cook for 3-4 minutes or until softened.
Stir in the salt, pepper, and poultry seasoning, and cook for an additional 30-60 seconds.
Remove the skillet from heat and let the mixture cool completely.
Add the dry bread cubes to a very large mixing bowl.
Stir in the cooled vegetable mixture until well combined.
Lightly beat the eggs and mix them into the bread mixture.
Add the fresh herbs and stir until everything is evenly combined.
Add the chicken broth to the mixture until the bread is moistened but not soggy.
Transfer the stuffing to the crockpot.
Cover and cook on high for 20 minutes.
Reduce the heat to low and cook for 3 hours or until the stuffing is set and lightly browned.
Transfer the stuffing to a serving bowl or directly from the crockpot.
Store any leftovers in the refrigerator.
Notes
To make the stuffing ahead of time, complete the steps until you put the mixture in the crockpot. Instead, cover and refrigerate until you’re ready to cook.