Spelt Crust Pizza with Fennel, Prosciutto, and Apples

Ingredients:
2 cups whole grain spelt flour (8 ounces)
2 teaspoons baking powder
3/4 teaspoon fine sea salt
1/2 teaspoon sugar
1 cup whole-milk ricotta cheese
1/4 cup whole milk
2 tablespoons linseed oil or extra-virgin olive oil
1 large egg
Coarse cornmeal, if using a pizza peel
4 or 5 green onions
1 cup sour cream
1/4 cup drained nonpareil capers
3/4 teaspoon freshly ground black pepper
1 Granny Smith apple, halved, cored, and sliced very thinly
1 fennel bulb, halved lengthwise, cored, and sliced very thinly
4 ounces thinly sliced prosciutto, cut crosswise into 1/2-inch-wide strips
Linseed or extra-virgin olive oil
for brushing

Instructions:
1 First, make the dough. To prepare the dough by hand: Whisk together the spelt flour, baking powder, salt, and sugar in a large bowl. Make a well in the center. In a small bowl, combine the ricotta, milk, linseed oil, and the egg and beat with a fork until smooth. Pour the ricotta mixture into the well. Combine with a dough whisk or a fork, stirring from the center and gradually incorporating the flour from the sides until a fairly moist dough comes together. To prepare the dough by food processor: Place the spelt flour, baking powder, salt, and sugar in the bowl and process for about 10 seconds. In a small bowl, combine the ricotta, milk, linseed oil, and the egg and beat with a fork until smooth. Pour the ricotta mixture across the top of the flour mixture and pulse, in 1-second intervals, just until a ball forms, 5 to 10 pulses. The dough will be fairly moist.
2 Transfer the dough to a well-floured work surface. Lightly flour your hands and briefly knead 5 to 7 turns to get a smooth yet slightly tacky dough. Wrap the dough in plastic wrap and let sit at room temperature for 30 to 45 minutes to allow the bran in the flour to soften.
3 Meanwhile, place a baking stone on a rack on the bottom shelf and preheat oven to 425°F. Liberally sprinkle a pizza peel with coarse cornmeal. Finely chop the white and light green parts of the green onions until you have 1/2 cup. Combine them with the sour cream, capers, and 1/4 teaspoon of the pepper in a small bowl. Finely chop the dark green parts as well (about 1/4 cup) and set aside for garnish.
4 Unwrap the dough, transfer to a lightly floured work surface and cut into 2 pieces. Keep 1 piece covered with plastic wrap. Lightly flour your hands and briefly knead the other until smooth, 7 to 10 turns. Using a rolling pin, roll the dough into an elongated pizza, 11 by 8 inches and about 1/4 inch thick. Do this in stages, occasionally turning the dough over and rolling it out further, lightly flouring your work surface and the rolling pin each time. Place the dough on the pizza peel. Spread half of the sour cream topping across, leaving a 1/2-inch border. Cover with half of the apple slices, top with half of the fennel slices, and sprinkle with half of the prosciutto. Brush the border with oil.
5 Slide the dough onto the baking stone and bake until the fennel just starts to brown at the edges and the rim turns golden brown and starts to crisp — it should yield when pressed with a finger — about 15 minutes. Use a large spatula to lift the edges of the pizza so you can slide the peel underneath; carefully transfer the pizza to a wooden board. Sprinkle with half of the reserved green onions and 1/4 teaspoon of the pepper. Cut with a sharp knife and serve at once. Repeat with the second pizza.