1. FOR THE DOUGH: In food processor fitted with metal blade, process flour, sugar, and yeast until combined, about 2 seconds. With machine running, slowly add water through feed tube; process until dough is just combined and no dry flour remains, about 10 seconds. Let dough stand 10 minutes.

2. Add oil and salt to dough and process until dough forms satiny, sticky ball that clears sides of workbowl, 30 to 60 seconds. Remove dough from bowl and knead briefly on lightly oiled countertop until smooth, about 1 minute. Shape dough into tight ball and place in large, lightly oiled bowl. Cover tightly with plastic wrap and refrigerate for at least 24 hours and up to 3 days.

3. FOR THE SAUCE: Whisk all ingredients except scallion greens together in medium bowl; refrigerate until ready to use.

4. TO BAKE THE PIZZA: One hour before baking pizza, adjust oven rack to second highest position (rack should be about 4 to 5 inches below broiler), set pizza stone on rack, and heat oven to 500°F. Remove dough from refrigerator and divide in half. Shape each half into smooth, tight ball. Place on lightly oiled baking sheet, spacing them at least 3 inches apart; cover loosely with plastic wrap coated with nonstick cooking spray; let stand for 1 hour.

5. Coat one ball of dough generously with flour and place on well-floured countertop. Using fingertips, gently flatten into 8-inch disk, leaving 1 inch of outer edge slightly thicker than center. Lift edge of dough and, using back of hands and knuckles, gently stretch disk into 12-inch round, working along edges and giving disk quarter turns as you stretch. Transfer dough to well-floured peel, and stretch into 13-inch round. Using rubber spatula, spread 1/2 of ricotta mixture in thin layer over surface of dough, leaving 1/4-inch border around edge. Sprinkle 1/4 cup Pecorino Romano evenly over sauce, followed by 1 cup mozzarella. Dollop 1/4 cup ricotta in teaspoon amounts evenly over pizza. Slide pizza carefully onto stone and bake until crust is well browned and cheese is bubbly and beginning to brown, about 10 to 12 minutes, rotating halfway through. Remove pizza and place on wire rack 5 minutes before slicing and serving. Repeat step 5 to shape, top, and bake second pizza.

Yield: two 13-inch pizzas