Pressed (optional) Salt Freshly ground black pepper In a large bowl, combine the mozzarella, ricotta, and 1/4 cup of the Parmesan; reserve. Roll out or stretch the pizza dough into circles. Working with 1 circle at a time, place the dough on a pizza pan generously sprinkled with cornmeal or on a lightly oiled pizza screen. Brush dough all over with olive oil, then cover half of dough circle with a generous portion of the cheeses, leaving a 1/2-inch border around the edges. Sprinkle with the tomatoes, prosciutto, garlic, and salt and pepper to taste. Fold the uncovered side over the filling and press the edges of the dough together to seal. Brush the dough with olive oil. Transfer to an oven preheated to 500 degrees and bake until the crust is golden brown and puffy, about 15 minutes. Remove from the oven to a plate, lightly brush with olive oil, sprinkle with Parmesan cheese, and serve immediately. Serves 4 to 6 as a main course, 8 to 10 as a starter.