Mix water, yeast, and sugar in a large bowl. Let rest in a warm location until bubbling.
Add the oil and flour to the bowl, mixing to incorporate. Work until mixture comes together into a rough dough. Transfer to a lightly floured surface and sprinkle salt overtop. Knead until smooth and elastic. Add flour as needed if dough is too sticky to work.
Shape the dough into a ball and place in a lightly greased bowl. Cover and let rise in a warm location until doubled in size. 20 minutes before dough is done rising, submerge the clay cooker in cool water and let soak.
Drain the the clay cooker and pat dry. Punch down the dough, form into a loaf, and transfer to the cooker. Cover loaf with lid and let rise in a warm location until almost doubled again.
Place the closed clay cooker in the cold oven and set to 475.F. Bake 45 minutes, then remove lid and continue baking until golden.
Let cool briefly in the cooker, then turn out onto a rack to finish cooling.
Forgot to add the oil at first, which I only realized after wondering why the dough was so stiff. Ended up kneading it in to the dough which still felt stiffer than usual. The crust is nice and crisp, if not a little tough. Beautiful color but still not as much rise as I would like.
Made this ~1 week ago. Didn't slice before baking this time and it turned out much better. It still isn't a huge loaf, but could reasonably be used as a small sandwich bread. Went great in butternut squash soup. The crust is very nice and slightly flaky, and the bread is nice and chewy.
Made this ~3 weeks ago. Gave the loaf a slice down the center before baking, which resulted in the loaf falling disappointingly. It was still good, but too small to be used as sandwich bread.
Forgot to soak Rompertopf so just baked in a bread pan. I (wrongly) assumed it would rise more, and I didn't have a second bread pan to invert on top of the other, so I baked uncovered the whole 45 minutes. By that time the top was quite dark (a bit too dark for some). I also added a pan of water to the oven to replace the steam missing from the Romertopf, but I'm not sure that really did much. Again, this barely rose and is quite a small loaf. Measured to just over 1 lb. - will use for Thanksgiving dressing rather than eating plain.