Stir together sugar, yeast, and 1 1/4 cups lukewarm water (105°–115°F) in small bowl. Let stand 5 minutes, or until mixture looks foamy.Whisk together flours, cornmeal, oil, and salt in bowl. Stir in yeast mixture, adding more warm water if necessary to make moist dough.Transfer dough to floured work surface, and knead 5 minutes, or until smooth and elastic. Transfer dough to large bowl rubbed with oil, and turn to coat with oil. Cover with kitchen towel, and let rise in warm place 1 hour.Punch down dough, and knead 2 minutes. Return to bowl, and let rise 1 hour more.Preheat oven to 500°F. Rub 2 baking sheets with oil. Divide dough into 2 pieces. Roll out each piece into 12- x 9-inch rectangle or 12-inch round. Transfer to prepared baking sheets, prick crusts all over with fork, and bake 5 minutes, or until set but not browned. Cool on wire rack before adding toppings.