Make Dough: In a large mixing bowl, whisk together flour, salt, sugar, and yeast. Pour water over dry ingredients and stir until no dry spots remain. The dough will be very sticky, but just scrape down the sides as you stir.
First Rise (60 minutes): Cover the dough with a clean dish towel and leave it on the kitchen counter to rise until doubled in size, 60 minutes. (If your kitchen is on the colder side, let the dough rise for 75 minutes.)
Heat Oven: Once dough has finished the first rise, preheat oven to 425°F / 218°C.
Rub softened butter over the inside of a 2.5-quart oven-safe bowl (or a 2.5-quart round / oval casserole dish).
Use a spatula to ease the dough into the buttered bowl.
Second Rise (20 minutes): Place dough near the oven and let it continue to rise, uncovered, for 20 minutes more.
Bake bread (40 minutes): Bake bread until the top is golden brown and very crisp, 40 to 45 minutes. (Use an instant read thermometer if you have one. The bread is done when it reaches 190°F / 88°C in the center.)
Remove the bread from the oven and flip it out onto a cooling rack so that it is upside down.
Allow bread to cool completely before cutting into slices or wedges. (Slicing the bread while still warm will cause it to compress and can give it a gummy texture in the center. Resist the urge to slice into the bread until it is completely cool.)