Dry or toast bread: Dry out the bread cubes by either leaving them out on a sheet pan overnight or baking them in a 350°F / 177°C oven, shaking the pan halfway through cooking, until golden and toasted, about 15 minutes.
Spray a 9x13 baking dish (or any 3 quart casserole dish) with nonstick cooking spray.
Meanwhile, heat a large skillet over medium heat. Add bacon and saute until browned and nearly crisp, 6 to 8 minutes. Transfer bacon to a paper-towel lined plate and return skillet to heat. Drain off all but a thin layer of baking grease from the pan.
Add butter to heated pan and gently stir it around until melted. Add celery, onion, garlic, sage, thyme, and parsley with a generous pinch of salt. Cook, stirring frequently and scraping up any browned bits on the bottom of the pan, until celery and onion are very soft, 10 to 12 minutes.
Pour butter and aromatics out over bread cubes (you can do this right on the sheet pan or transfer everything to a large bowl. Toss together until everything is evenly combined. Stir in half the bacon (reserve the rest as topping).
Transfer stuffing to baking dish.
Whisk eggs until even. Whisk in chicken stock and salt. Pour over stuffing.
Top stuffing with remaining bacon.
Cover stuffing tightly with foil. Refrigerate for 30 minutes. (This will allow the bread to soak up the liquids for a moist center and crisp top.)
Preheat oven to 350°F / 177°C.
Bake stuffing, covered, for 45 minutes.
Remove foil and continue baking until stuffing is golden brown on top, about 20 to 30 minutes more (depending on how crisp you like the topping).
Serve warm.