Prepare the Base: Preheat oven to 375°F. Line a baking sheet with parchment paper. Place bread cubes in a large mixing bowl.
Sauté Vegetables: In a large skillet, melt butter over medium heat. Add diced onion and celery, cooking for 8-10 minutes until softened and lightly golden.
Create Moisture: Gradually add chicken broth to the skillet, stirring to combine. Remove from heat and let cool slightly.
Combine Ingredients: Pour the broth mixture over bread cubes. Add beaten eggs, sage, thyme, salt, pepper, garlic powder, and parsley. Mix gently until well combined but not overmixed.
Add Optional Ingredients: Fold in cranberries and walnuts if using.
Form Balls: Using an ice cream scoop or large spoon, form mixture into golf ball-sized portions and place on prepared baking sheet.
Bake: Bake for 25-30 minutes until golden brown and crispy on the outside.
Serve: Let cool for 5 minutes before serving warm.