In a large bowl, whisk together 3 cups of bread flour, ½ cup of cocoa powder, and ¼ cup of sugar until well combined.

Next, stir in 1 cup of lukewarm water and ½ cup of your sourdough starter into the dry mixture, mixing until a shaggy dough forms.

Transfer the dough onto a floured surface and knead for about 10 minutes until smooth and elastic.

Gently fold in 1 teaspoon of salt and 1 cup of dark chocolate chips into the dough without overworking it.

Place the dough in a greased bowl and cover it, allowing it to rise for 4-6 hours until it doubles in size.

Gently punch down the dough, shape it into a loaf, and transfer it into a greased loaf pan.

Cover the loaf and allow it to rise for another 2-3 hours until it looks puffy.

Preheat your oven to 220°C (428°F) for about 30 minutes before baking.

Bake for 30-35 minutes until the crust is firm and sounds hollow when tapped.

Let the bread cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.