Sourdough Pan di Ramerino

Directions

1. Feed sourdough starter and soak the raisins (night before mixing at 9:00 p.m.)
   
   In a small airtight container with a lid, combine the raisins and 100 grams of the water (use enough water so they’re just covered). Cover the bowl and leave it out on the counter. Feed your sourdough starter around this time to give it 12 hours of fermentation time.
2. Mix the dough (9:00 a.m.)
   
   In the morning, your starter should be bubbly on top and at the sides, have risen in the jar, have a sour aroma, and with a loose consistency. If it was cold in your kitchen overnight or the starter isn’t displaying these signs, give it one more hour to rise and check again.
   
   To the bowl of a stand mixer fitted with the dough hook attachment, add the remaining 236 grams water, 460 grams flour, 151 grams ripe starter, 27 grams sugar, 9 grams salt, 1 of the eggs, and 1 egg yolk. With the mixer to low speed, mix until the ingredients are combined and no dry bits of flour remain. If the dough looks very dry, drizzle 1 scant tablespoon of water to the mixing bowl with the mixer running to help hydrate the flour. Increase the mixer speed to medium-low and mix for 5 to 6 minutes, until the dough starts to clump around the dough hook. At this point, the dough should be strong enough to partially pull away from the bottom and sides of the mixing bowl. If the dough still looks very wet and does not remove from the sides of the bowl, add more flour by the tablespoon and mix for another 1 to 2 minutes until incorporated.
   
   Let the dough rest for 10 minutes in the mixing bowl, uncovered.
   
   With the mixer on low speed, slowly drizzle in the olive oil in small bursts, about 4 to 6 minutes total. Once all of the oil is added, increase the mixer speed to medium-low and continue to mix until the dough smooths and once again begins clinging to the dough hook, 2 to 3 minutes. Scatter the rosemary on top of the dough. Drain the raisins of their water, squeezing out a bit more with your hands, and add to the top of the dough. With the mixer on to low speed, mix until the inclusions are mostly distributed, about 1 minute. At the end of mixing, the dough will be very soft, but will firm back up during bulk fermentation.
   
   Transfer the dough to another large container (or leave it in the mixing bowl) for bulk fermentation.
3. Bulk ferment the dough (9:30 a.m. to 1:30 p.m.)
   
   Cover the dough with a reusable airtight cover and let it rise at warm room temperature (76°F/24°C) for a total of 4 hours. During this time, you’ll give the dough two sets of “stretches and folds” (see next instruction for explanation) to give it additional strength.
   
   To stretch and fold: after 30 minutes of bulk fermentation, uncover the dough. Wet your hands, grab the north side (the side farthest from you) of the dough, and stretch it up and over to the south side. Then, stretch the south side up to the north. Then, perform two more folds, one from east to west and one from west to east. Cover the dough and let it rest for 30 more minutes, then give it another set of stretches and folds. Let the dough rest, covered, for the remaining 3 hours of bulk fermentation.
4. Divide and shape the dough (1:30 p.m.)
   
   Check the dough; after 4 hours, it should have risen in the bulk fermentation container, have a few scattered bubbles, be smoother, with a slightly domed top, and be moderately light and fluffy to the touch. If the dough still looks sluggish or feels dense after 4 hours, give it another 30 minutes to rise in a warm spot, like your oven turned off with the light on the inside (74 to 76°F/23 to 24°C).
   
   Line two 13x18-inch sheet pans with parchment paper. Flour the top of the dough and use a bowl scraper to gently scrape it out onto a work surface, flour-side down. Flour the (new) top of the dough. Using a bench scraper and floured hand, divide the dough into 12 (90-gram) pieces (you might have a little scrap dough leftover: discard or bake it off).
   
   Using as much flour as necessary to help prevent the dough from sticking to your hands and the work surface, shape each of the 12 pieces of dough into a very tight ball by pushing, twisting, and dragging the dough against the work surface with the bench scraper. Pushing and pulling will create tension on the top of the dough, creating a uniformly smooth surface.
   
   After shaping each ball, transfer to a prepared sheet pan (6 per pan with even spacing between them). Cover the sheet pans with a large plastic bag, plastic wrap, or sheet pan cover and seal.
5. Proof dough (1:45 p.m. to 4:45 p.m.)
   
   Proof the dough at a warm temperature (74 to 76°F/23 to 24°C is ideal) for about 3 hours. If your kitchen is on the cool side, expect the dough to take longer to proof. Extend the proof time as necessary until the dough is puffy—a gentle poke should feel like poking a marshmallow.
6. Bake and finish (4:45 p.m.)
   
   Heat the oven to 425°F (220°C) with racks in the top and lower third. In a small bowl, whisk together the remaining 1 egg and 15 grams of milk for the egg wash.
   
   Using a pastry brush, lightly brush the surface of each piece of dough with the egg wash. Using a razor blade, baker’s lame, or sharp knife, score each piece of dough at the top-center with a pound sign (“#”) on top. Due to the soft dough, it can be challenging to score: move quickly with your blade, but it’s okay if the score isn’t clean and precise (they’ll bake up delicious regardless). Slide the sheet pans into the oven, and bake for 20 minutes. Rotate the baking sheets back to front and top rack to bottom rack. Reduce the oven to 350°F (175°C) and bake for another 15 to 20 minutes, until the buns are golden-brown and the internal temperature is around 200°F (93°C).
   While the buns bake, make the simple syrup, in a small saucepan over medium heat, bring the 50 grams of water to a boil. Once boiling, pour in the 50 grams of sugar, stirring to help dissolve. Bring back to a boil then remove from the heat. Set aside to cool.
   
   Remove the buns from the oven, and using a pastry brush, immediately apply a thin layer of the simple syrup (you will have some leftover, see headnote). Let the buns cool for 15 minutes before eating.
   
   These buns are best the day they're baked but keep in an airtight container and on the counter. Reheat them in a 350°F oven for a few minutes before serving.