10:00 PM – Starter Build: In a small glass jar, add your 5g of starter culture to 35g of water and whisk together cleanly. Stir in 30g of all-purpose or bread flour and 5g of rye flour. Mix thoroughly, cover loosely, and let it sit at room temperature 74–78°F (23–26°C) overnight for 8 to 10 hours until the starter reaches its peak and at least triples in volume.

8:00 AM – The Cocoa Autolyse: In a large bowl, thoroughly whisk together the 255g of bread flour, 30g of whole wheat flour, 15g of cocoa powder, and 25g of sugar until completely uniform. Pour in 207g of water and mix with a spoon just until all dry flour patches entirely disappear. Cover tightly and let it rest on your counter for 1 full hour to completely hydrate the cocoa and flour proteins.

9:00 AM – Sourdough Starter Integration: Add 60g of your active overnight starter peak directly into the dark, autolysed dough. Knead by hand or mix on low speed for 2 to 3 minutes until the starter is completely incorporated. Cover and let rest for 30 minutes.

9:30 AM – Bassinage & Salt Incorporation: Add your 6g of salt along with the remaining 30g of cold bassinage water into the bowl. Squeeze and knead the dough for 3 to 5 minutes until the extra liquid is fully absorbed and a cohesive, dark dough forms. Cover and let rest for 30 minutes at a stable warm temperature of 74–78°F (23–26°C).

10:00 AM – Chocolate Lamination: Spray your clean work surface lightly with water and wet your hands. Gently tip the dark dough out and stretch it out into a wide rectangle as thin as possible across the table without tearing the matrix. Scatter all 75g of chocolate chips or chunks evenly over the entire surface. Fold the dough cleanly over onto itself into a neat package to trap the chips, return it to your bulk container, and let rest for 45 minutes.

10:45 AM – 1st Stretch & Fold: Wet your hands slightly. Lift one side of the dough up cleanly from the container edge and fold it directly over the center. Repeat this action for all four quadrants of the dough mass to build structured vertical strength and distribute the chocolate chips. Cover and let rest for 45 minutes.

11:30 AM – 2nd Stretch & Fold: Execute your second structured round of quadrant folds to continue organizing the expanding gluten network. Cover and let rest for 45 minutes.

12:15 PM – 3rd Stretch & Fold: Execute the third and final stretch-and-fold round. Cover and let the dough proof completely untouched for 30 minutes at a warm 76–80°F (24–27°C). The dough should look visibly lighter, show distinct surface bubbles, and hit a clean 50% volume rise.

12:45 PM – Preshaping: Gently tip the expanded dough out onto your work surface and dust the top lightly with flour. Flip the mass over so the floured side faces directly down. Fold the outer edges cleanly onto itself so that the raw flour coating remains entirely on the outside of the loaf. Round the dough into a loose ball and let it rest on your counter completely uncovered for 30 minutes to relax the gluten network.

1:15 PM – Final Shaping: Dust the top of the resting dough round with flour. Use a dough scraper to flip it over onto your counter so the floured side faces down. Starting at the edge closest to you, pull the two right corners of the dough outward and fold them up into the center. Repeat this exact matching movement across the left side. Roll the dough tightly away from you, shaping it into a perfectly smooth, taut, uniform boule or batard.

Basket Stabilization & Fridge Retard: Transfer the shaped roll seam-side up into your well-floured proofing basket. Cover with plastic wrap and return the basket to a warm 80°F (27°C) spot for exactly 15 minutes to stabilize. Slide the basket directly into your refrigerator to rise slowly for 14 to 24 hours of cold fermentation retard at a stable 40°F (4°C).

Next Morning – Preheating: Preheat your oven to 500°F (260°C). Place your cast iron pan and lid onto the middle rack to heat up thoroughly for 45 minutes to 1 hour.

Scoring & Loading: Remove the cold chocolate dough basket from the fridge. Flip it over gently onto a sheet of parchment paper and score the dark surface with one clean, long, deep cut using a sharp lame or razor blade.

The Steam Bake: Transfer the dough carefully onto the smoking hot cast iron pan base, drop the heavy lid down tightly to lock in the steam, and bake at 500°F (260°C) with the lid on for exactly 15 minutes.

The Open Bake: Carefully lift the hot lid off to expose the loaf, lower the oven temperature to 450°F (232°C), and continue baking bare for an additional 20 minutes until the crust is deeply caramelized and crisp. Let cool on a wire rack for 2 full hours before slicing!