TO FILL, SHAPE, AND BAKE THE DOUGH
1 Line a half sheet pan with a silicone baking mat or parchment paper. (Cleanup will be easier with the silicone mat. This loaf will not be transferred to a different pan before baking.)
2 Lightly dust the work surface and your hands with flour. Using a bench scraper, divide the dough into 4 equal pieces. Press each into an 8-inch (20 cm) square. Spoon 100 grams (about 2/3 c) of the ciccioli evenly over the top of each, then scatter 80 grams (about 1/2 c) of the diced Taleggio over each piece of dough.
3 Working with one square at a time, start at the top and roll the dough over on itself about a quarter of the way down the square. Roll two more times, ending with the dough seam-side down. Carefully move the square to another floured spot on the work surface to be sure it isn’t sticking. Gently press the top of the dough to form a rectangle measuring about 4 by 8 inches (10 by 20 cm); it’s okay if some of the filling breaks through as you do so. Starting again at the top, make one fold along the length of the rectangle, folding the dough in half and ending with the seams touching. Transfer to the lined pan and repeat with the remaining rectangles. Dust the top of the loaves with the dusting mixture, then cover with a clean kitchen towel. Transfer the pan to the refrigerator and chill for 12 to 20 hours.
4 Set up the oven with a cast-iron skillet for steam (see Baking Stones and Steam, then preheat the oven to 450°F (230°C).
5 Transfer the sheet pan to the oven. (These loaves are not scored.) Using heavy-duty oven mitts or potholders, pull out the hot skillet, add about 3 cups of ice cubes, then slide it back in and close the oven door. Bake, rotating the pan about two-thirds of the way through baking, until the tops are dark and crispy, about 20 minutes. (If you used a dark buckwheat flour, it may be hard to gauge much of a color difference, but the appearance will no longer be raw.)
6 Set the sheet pan on a cooling rack. It’s very likely that some cheese will have escaped during baking. Don’t worry about it. If it has, give it a couple of minutes to cool. Then lift the loaves from the pan. The cheese can be pressed back onto the loaves or kept as a quick snack for the cook.
7 Let the bread cool completely before eating, about 2 hours. This bread is best eaten the day it is baked.
