Dry the bread cubes: Spread cubed bread on a baking sheet and let it sit out overnight, or toast at 300°F for about 15 minutes until dry and slightly crisp. This keeps the stuffing from turning soggy once the broth is added.
Cook onion and celery: Melt butter in a large skillet over medium heat and cook the onion and celery until soft and translucent, about 6 minutes, stirring occasionally.
Brown the sausage: Add the turkey sausage to the skillet and cook, breaking it into small pieces, until no pink remains, about 6 minutes.
Stir in the herbs: Add the sage, thyme, and rosemary to the skillet and cook for 1 minute, until fragrant.
Combine with bread: In a large bowl, toss the dried bread cubes with the sausage and vegetable mixture, salt, and pepper until evenly coated.
Whisk broth and eggs: In a separate bowl, whisk the chicken broth and eggs together until smooth.
Moisten the mixture: Pour the broth mixture over the bread and stir gently until every cube looks moistened but not soaked through.
Fold in parsley: Stir in the fresh parsley for a bright, grassy finish before transferring the mixture to the baking dish.
Fill the baking dish: Butter a 9x13-inch baking dish and spread the stuffing mixture evenly, pressing it down lightly with a spatula.
Bake until golden: Bake at 375°F for 35 to 40 minutes, until the top turns deep golden brown and the edges crisp and pull slightly away from the dish.
Rest before serving: Let the stuffing rest for 5 minutes before serving so the center sets slightly and holds its shape when scooped.