Dissolve sugar and yeast in warm water in a large bowl; let stand 5 minutes. Lightly spoon flour into dry measuring cups; level with a knife. Add flour, cornmeal, oil, and salt to yeast mixture; stir until a soft dough forms. Turn dough out onto a floured surface. Knead 5 minutes. Add 2 tablespoons bread flour, as needed, to prevent dough from sticking to hands (dough will feel tacky).
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 45 minutes or until doubled in size. (Gently press two fingers into dough. If indentation remains, dough has risen enough.) Punch dough down; shape into a ball. Lightly respray bowl; place dough in bowl, turning to coat top. Cover; let rise in a warm place (85°), free from drafts, for 30 minutes.