1. Let the dough stand at room temperature, covered, for 30 minutes.
2. Place a pizza stone or heavy baking sheet in oven. Preheat oven to 500° (keep pizza stone or baking sheet in oven as it preheats).
3. Roll the dough into a 14-inch circle on a lightly floured surface, and pierce entire surface liberally with a fork. Carefully remove pizza stone from oven. Sprinkle cornmeal over pizza stone; place dough on pizza stone. Spread sauce over dough, leaving a 1/2-inch border; top with cheese. Bake at 500° for 14 minutes or until crust is golden and cheese is lightly browned. Remove from oven; brush outer crust with olive oil. Arrange prosciutto over pizza; top with oregano. Cut into 6 large slices.