After you've made the dough, divide it in half and let come to room temperature, uncovered, about 1 hour. Meanwhile, place a pizza stone or an inverted baking sheet on the oven floor and preheat to 500˚.
On a lightly floured surface, stretch or roll out 1 piece of dough into a 12-inch round, about ⅛ inch thick. Dust a pizza peel or another inverted baking sheet with cornmeal and lay the dough on top.
Spread half of the fig spread on the dough, leaving a ½-inch border around the edge. Sprinkle with half of the mozzarella.
Slide the pizza onto the hot stone or baking sheet and bake until the crust is browned, 10 to 12 minutes. Repeat with the remaining dough and toppings.
Meanwhile, toss the arugula, olive oil and lemon juice in a bowl and season with salt and pepper. Pile the prosciutto and arugula salad on top of the pizzas. Makes 2 12-inch pizzas.
