Mix cocoa powder and salt with flour in a large bowl until well dispersed

Mix in the rest of the ingredients, mix well for a few minutes and let sit for 10 minutes

Over a period of one hour, do 3 sets of stretch and folds, flipping the dough upside down after each set

Cover the bowl with plastic wrap and place in refrigerator overnight for about 10-12 hours

Turn the dough on a lightly floured work surface. Divide into 3 equal parts and shape into rectangles. Let rest for 15 minutes

Starting preheating oven to 490F, with the 14x16 inch baking stone on the top rack and a bread pan filled with hot water on the bottom rack

Stretch each dough rectangle slightly and fold into a cylinder, sealing the seams. Using your hands, roll the cylinders gently stretching them to desired length, about 14-15 inches

Place on a floured surface, seam side up, side by side. Cover with plastic wrap and prop from each side to ensure the baguettes hold their shape

Proof at room temperature for about 30 minutes

Remove plastic wrap, pull baguettes apart. Turn them seam side up and dust off excess flour. Using a sharp knife or a razor blade, make 3-4 scores on each baguette. When scoring, use a swift and firm motion to ensure nice and clean cuts

Open the oven, taking caution not to get burned by steam, and slide baguettes off onto baking stone. Close oven and reduce temperature to 480F

Bake for 15 minutes

Rotate, drop temperature to 450F and continue baking for another 10-15 minutes, until deep brown