In a large mixing bowl, add water and sourdough starter, and whisk until combined.

Add flour and cocoa powder, if you are wanting to add sugar do so now as well. Mix until it comes together in a shaggy dough. Keeping your hands wet to mix is very helpful.

Let dough sit and autolyse for 30 minutes.

Add salt and chocolate chips (If using), pinch and work salt in.

Let rest for 1 hour.

Fold series: First set of folds; you can do either stretch & folds, or coil folds. Let rest for 1 hour.

Repeat every hour 3- 4 times.

After your final fold series, put dough in the fridge for 10- 12 hours. This can be less or more depending on how your timing is working out.

When you are ready to shape, take dough out of the fridge and allow it to warm up for 30 minutes.

Shape dough and place in banneton basket.

Allow dough to settle in your banneton, and then sew it up before putting back in the fridge for its final cold proof, for 12 hours.

Preheat your oven with dutch oven inside, to 450F.

Once oven is heated, take dough out of the fridge, and turn out onto some parchment paper.

Score bread by slicing about a 1 inch cut across your bread, to allow steam to escape. You can use a razor blade or a very sharp knife. (If you want you can do some fancy designs as well).

Place into preheated dutch oven.

Bake at 450F for 23 minutes, lower to 425F for 15 minutes.

Take out of the oven and allow to cool on a cooling rack.

Wait until the loaf is totally cooled before cutting into.

Enjoy with butter! Peanut butter, or cream cheese!