Combine sponge ingredients in a large or mixer bowl and whisk until very smooth, to intentionally incorporate air — this will yield a thick batter. Set it aside.

In a separate large bowl, whisk together the flour mixture and gently scoop it over the sponge to cover it completely. Cover the bowl tightly with plastic wrap and allow it to ferment for 1 to 4 hours at room temperature. (The sponge will bubble through the flour mixture in places.)

Add the oil and mix with the dough hook on low speed for about 1 minute, until the flour is moistened enough to form a rough dough. then raise the speed to medium and mix it for 10 minutes. The dough should be very smooth and elastic, and it should jump back when pressed with a fingertip; if it is sticky, turn it out on a counter and knead in a little extra flour.

Add the oil and, with a wooden spoon or your hand, stir until the flour is moistened. Knead the dough in the bowl until it comes together, then scrape it onto a very lightly floured counter. Knead the dough for 5 minutes, after which it might be a little sticky. Cover it with the inverted bowl and allow it to rest for 20 minutes. Knead the dough for another 5 to 10 minutes or until it is very smooth and elastic.

Place the dough in a large container or bowl, lightly oiled. Oil the top of the dough as well. Allow the dough to rise until doubled, 1 1/2 to 2 hours.

Flip the bowl over and let the dough fall out on to a lightly floured counter, press it down gently, fold or form it back into a square-ish ball and allow it to rise a second time, back in the bowl covered with plastic wrap for about 45 minutes.

Turn the dough out onto a lightly floured counter and gently press it down again. Round it into a ball and set it on a cornmeal sprinkled baking sheet. Cover it with oiled plastic wrap and let it rise until almost doubled, about 1 hour to 1 hour 15 minutes.

Preheat the oven to 450°F. On a shelf at the lowest level, place a baking sheet or bread stone. [Optionally, place a cast-iron skillet or sheet pan on the floor of the oven to preheat.]

With a sharp knife or singled-edged razor blade, make 1/4- to 1/2-inch-deep slashes in the top of the dough. Mist the dough with water and quickly but gently set the baking sheet on the hot stone or hot baking sheet. [Optionally: Toss 1/2 cup of ice cubes into the pan beneath and immediately shut the door.]

Bake for 15 minutes, lower the temperature to 400°F and continue baking for 30 to 40 minutes or until the bread is golden brown and a skewer inserted into the middle comes out clean (or a thermometer inserted into the center reads 190°F).

Cool the bread on a wire rack.