Preheat your oven to the highest temperature possible.
Form the pizza dough into a ball. Start by making a circular motion with the palm of your hand, with some pressure. Then release the pressure gradually until you get a nice ball shape. Put the dough ball on a lightly floured work surface. Dust them with some more flour, and let them proof covered with a kitchen towel for another 15 minutes.
Shape the dough into a large, thin disc and place it in a pizza pan.
Spoon the tomato purée (passata) onto the center of the dough. Using the back of a spoon or a ladle, spread the tomato in circular motions toward the edges. Leave a border about 1 inch (2–3 cm) wide.
Drizzle with a few drops of extra virgin olive oil, then sprinkle with dried oregano and salt.
Add the mozzarella. Tear it into bite-size pieces and place them over the tomato sauce.
Arrange the prosciutto slices over the pizza, covering everything except the edges.
Transfer the pizza to the oven. Bake for 10 minutes, or until the edges are lightly browned.