If your bread is fresh, preheat the oven to 250°F. Spread the bread cubes evenly on a baking sheet and bake for 20–25 minutes, stirring halfway through, until the bread is completely dry and firm. Set aside to cool slightly and then turn oven up to 350°F.

​While the bread bakes, heat a large skillet over medium heat. Add the bacon and cook until crisp, about 5 minutes. Stir in the butter, then add the onion, celery, sage, poultry seasoning, salt, and pepper. Sauté over medium-low heat until the vegetables are soft and fragrant, about 5–10 minutes. Remove from heat and let cool slightly.

​In a medium bowl, whisk together the chicken broth and beaten egg.

​In a large mixing bowl, add the toasted bread cubes and the sautéed vegetable mixture. Pour the broth and egg mixture over the top and toss gently until evenly coated. If the stuffing seems too dry, add a little extra broth until it reaches your desired consistency.

Lightly spray a casserole dish with cooking spray. Spoon the stuffing mixture into the dish and spread it evenly.