Mix all the flours along with cocoa powder and Mexican chocolate powder in 365 g of water in a large bowl. And mix by hand until there are no dry bits. Knead for 1-2 minutes until well combined. Cover and let rest for 30 minutes to one hour.

After autolyse with flour incorporate the sourdough starter into the dough

Then after 30 minutes add salt. Mix well and cover the dough again and set aside.

Then stretch and fold the dough every 1 hour for until 2 hours. This means grabbing the underside of the dough and stretching it up and over the rest of the dough. Perform a few of these turns each time you handle the dough.

About 1 hour remaining to laminate the dough, soak craisins in water and set aside. When you are ready to use you need to strain the water

One hour after last stretch and fold do a lamination of the dough. Means spread the dough into thin sheet and fold them into a letter fold. To this incorporate raisins.

After one hour , transfer the dough lightly floured workspace and shape them into round Boule. Fold the third of the dough closest to you inward, and then stretch the dough out to the sides. Fold the right, and then left sides in toward the center. Fold the top of the dough inward, and then wrap the bottom part of the dough over it all. If you want, you can make pre-shape and set aside for 15 minutes and then make a final shape.

Work this into a round shape, and place seam side up in a proofing basket lined well with flour.

After transferring to Banneton, Let rise the dough overnight in the refrigerator. You can keep this cold retard up to 14 hours.

When you are ready to bake preheat oven to 475°F.

Remove the dough from the proofing basket and score and transfer to Dutch oven and close the lid and immediately place the top back on and return to the oven.

If you want crackling crust after switching off the oven keep oven door ajar and keep the bread inside.

once bread comes out of oven cool completely in the wire rack and cut it into slice and enjoy with some butter