Chocolate pan de cristal rolls

Weigh 500 g bread flour, 10 g salt, 2.5 g yeast and 21 g cocoa powder into a bowl and stir.

Add 520 g water warmed to about 100 (cooler water in summer) and stir to a soupy dough; scrape down the bowl early.

Spread a tablespoon of olive oil in an eight inch brownie pan and scrape the batter-like dough into it; cover and leave 20 minutes.

With a wet hand, give a bowl fold: stretch each corner out and let it fall to the middle, working around; cover 20 minutes.

Give a coil fold: lift from the midline with wet hands so the dough stretches and coils under itself, turn the pan, repeat; cover 20 minutes. Repeat twice more, 20 minutes apart, doing fewer coils as the dough strengthens.

After 20 more minutes, mist the counter with water, invert the dough onto it and stretch it to about 14 by 10 inches with damp hands.

Scatter the chopped chocolate evenly; letter-fold the sides in by thirds, then fold from the top and roll down from the bottom.

Return to the pan, cover and rest about an hour and 20 minutes until jiggly and well risen.

Turn out onto a generous layer of bread flour, flour the top, and cut by eye into halves, quarters, then eight pieces; flour any sticky exposed side to protect the chocolate from burning.

Proof on parchment, uncovered, for two hours at room temperature until an indent holds and the surface bubbles.

An hour ahead, preheat the oven to 475 with a baking stone in the lower third.

Slide the rolls onto the stone from a flat tray and bake 10 to 12 minutes, then move them up off the stone for about eight minutes more, to the colour you like.

Serve at once, while crisp.