1. Feed Your Starter: Make sure your sourdough starter is active and bubbly before you begin.

2. Mix the Dough: In a large bowl, gently combine the water, your bubbly sourdough starter, sugar, and vanilla extract or scraped vanilla bean seeds. Stir these together until they are well mixed. Then, add the bread flour, cocoa powder, and fine sea salt. Mix everything with your hands or a sturdy spoon until there’s no dry flour left and the mixture just comes together. This initial mix is the start of your chocolate sourdough bread dough.

3. Rest (Autolyse): Now, cover your bowl with a clean kitchen towel or plastic wrap and let the dough rest for about 30 minutes to 1 hour. This resting period, called autolyse, allows the flour to fully hydrate and the gluten to start developing on its own.

4. Incorporate Add-ins: After the rest, it’s time for the delicious additions! Sprinkle the chopped walnuts, raisins, and semi-sweet chocolate chips over the dough. Using damp hands, gently knead or fold them into the dough until they are evenly distributed. Be careful not to overwork the dough at this stage.

5. Bulk Fermentation & Folds: Cover the bowl again and let it sit at room temperature for 3 to 5 hours, depending on how warm your kitchen is. During this “bulk fermentation” time, perform “stretch and folds” every 30-60 minutes for the first 2-3 hours. To do a stretch and fold, wet your hand, grab a portion of the dough from the edge, stretch it up, and fold it over the center. Rotate the bowl and repeat this 3-4 times.

6. Pre-Shape: Once your dough has visibly risen and feels light and airy, gently tip it out onto a lightly floured surface. Using a bench scraper or your hands, carefully shape the dough into a loose round. Let this pre-shaped dough rest uncovered for 20-30 minutes.

7. Final Shape: Now it’s time to give your chocolate sourdough bread its final form. Lightly flour your hands and the work surface. Gently turn the dough over. Using your hands and the bench scraper, create a tight, round or oval shape with good surface tension.

8. Cold Proof: Lightly flour a banneton basket or a bowl lined with a floured towel. Carefully transfer your shaped chocolate sourdough bread dough into it, seam-side up. Cover it tightly with plastic wrap and place it in the refrigerator for at least 8 hours, or ideally overnight (up to 24 hours).

9. Preheat & Bake: When you’re ready to bake, preheat your oven to 475°F (245°C) with your Dutch oven inside for at least 30-45 minutes. Carefully remove the hot Dutch oven. Gently tip your cold chocolate sourdough bread dough into it (you might use parchment paper to help). Score the top of the dough with a sharp knife or razor. Bake covered for 25-30 minutes, then uncover and bake for another 15-20 minutes, or until the crust is deep golden brown and sounds hollow when tapped.

10. Cool Completely: Once baked, immediately remove your gorgeous chocolate sourdough bread from the Dutch oven and place it on a wire rack. It’s crucial to let it cool completely for at least 2-3 hours before slicing.