Combine warm water, yeast, and sugar in a large bowl. Let sit until foamy, about 10 minutes.
Add flour and salt to the yeast mixture. Mix until a shaggy dough forms. If dough is too wet, add 1 tablespoon more flour at a time until it reaches the right consistency.
Cover the bowl with a damp cloth and let rise in a warm place until doubled in size, about 1 hour.
Turn the dough onto a lightly floured surface. Gently shape into a round loaf without deflating too much. Place on a cornmeal-dusted baking sheet. Cover and let rise for 30 minutes.
Preheat the oven to 450°F during the second rise.
Dust the loaf with flour and slash the top with a sharp knife. Bake in the preheated oven for about 35 minutes or until golden brown.
Remove the bread from the oven and let it cool on a wire rack for at least 20 minutes before slicing.