1. Whisk sourdough starter and warm water in a large bowl until frothy.

2. Add flours, cinnamon, and brown sugar; stir to form a rough dough and rest 30 minutes.

3. Sprinkle salt and drizzle melted butter; fold until evenly incorporated.

4. Knead or use stretch-and-fold every 30 minutes for 2 hours.

5. Gently fold in diced pears and optional nuts or raisins.

6. Cover and bulk ferment 4–6 hours until doubled.

7. Shape dough into a loaf, place seam-side up in a floured proofing basket, and proof 1–2 hours or refrigerate overnight.

8. Preheat oven and Dutch oven to 425°F (220°C).

9. Invert dough onto parchment, score the top, place in Dutch oven and bake covered 25 minutes.

10. Remove lid and bake 15–20 minutes until golden crust forms.

11. Cool on a rack for at least 1 hour before slicing.