Place a pizza stone or upside-down baking sheet in the oven and preheat to 450 degrees F. Roll out the dough on a lightly floured surface into a 12-inch round. Transfer to a cornmeal-dusted pizza peel or another upside-down baking sheet; slide the dough onto the hot pizza stone or baking sheet. Bake 8 minutes. Meanwhile, combine 2 tablespoons olive oil in a bowl with the garlic, rosemary, and salt and pepper to taste.
Remove the pizza from the oven, brush with the olive oil mixture and top with the ricotta and mozzarella. Return the pizza to the oven; bake until the cheese is golden and bubbly, about 6 more minutes.
Meanwhile, toss the arugula and shallot in a large bowl with the lemon juice, the remaining 2 tablespoons olive oil, and salt and pepper to taste. Top the pizza with the arugula salad, prosciutto and shaved parmesan. Cut into slices.