Cut or tear the bread into 1- to 2-inch pieces. Spread the bread pieces onto a dry baking sheet and bake at 250°F for about 1 hour, stirring occasionally, until the bread is dry and toasted but not browned.

While the bread is toasting, chop the onion and dice the celery into approximately 1/4-inch pieces. Finely chop the parsley, sage, rosemary, and thyme.

Preheat the oven to 350°F.

In a large skillet over medium heat, melt the 1 cup of butter. Add the chopped onion and celery and sauté for 7 to 10 minutes, or until softened but not browned.

Place the toasted bread pieces in a large mixing bowl. Add the chopped parsley, sage, rosemary, and thyme.

Add the cooked onion and celery mixture, including all of the melted butter, to the bowl with the bread and herbs.

Season with the kosher salt and black pepper. Stir until the bread is evenly coated and the ingredients are well distributed.

In a separate bowl or large measuring cup, whisk together the broth and eggs until fully combined.

Gradually pour the broth mixture over the bread mixture in increments, gently tossing after each addition. Use your hands or a large spoon to combine until the bread is evenly moistened. The stuffing should be moist but not soggy, and there should be no liquid pooling in the bottom of the bowl. Add up to 1/2 cup additional broth if needed.

Grease a 9x13-inch baking dish with the softened butter. Transfer the stuffing mixture to the prepared dish and spread it evenly to the edges.

Cover the dish with foil and bake at 350°F for 40 minutes.

Remove the foil and continue baking for an additional 25 to 35 minutes, or until the top is golden brown and crisp to your preference.

Serve warm.