Preheat your oven to 300°F (150°C).

Cube the sourdough bread and spread pieces evenly on baking sheets. Toast in the preheated oven for 25 minutes, tossing halfway through.

Melt unsalted butter in a large skillet over medium-high heat. Add diced celery and onion. Sauté for 7-8 minutes until softened.

Stir in diced Honeycrisp apples, dried cranberries, thyme, rosemary, and sage. Sauté for another 3-4 minutes.

In a large mixing bowl, combine toasted sourdough and sautéed vegetables. Add the egg and chicken broth. Mix gently until moistened.

Transfer mixture to a greased 9x13 baking dish, pack gently. Cover with foil and bake for 15 minutes.

Remove foil and bake for an additional 20 minutes until the top is golden brown.