Directions

1. Separate rolls onto a cornmeal-sprinkled work surface. Cover with plastic wrap and let rest while preparing filling.
2. Heat oil in 12-inch skillet over medium-high heat. Add onion; saute until tender and golden, 2 to 3 minutes. Add spinach, garlic and nutmeg; saute, breaking up large clumps with a wooden spoon, until heated through, 2 to 3 minutes. Add salt and pepper. Transfer to a medium bowl; stir in ricotta. Let cool; stir in remaining cheeses.
3. Adjust oven rack to center position and heat oven to 450 degrees.
4. Sprinkling with cornmeal as necessary, roll out each roll into a 7-inch circle. Spoon a scant 1/2 cup of filling just below the center line, leaving a 1-inch border along the bottom half of the dough circle. Spoon filling just below the center line of the circle of dough, leaving a border along the bottom half of the circle. With wet fingertips, moisten the bottom border. Fold dough over filling and press edges together. Thoroughly seal by using fingertips to crimp and flute the edges or by pressing with the tines of a fork. Place on a large cookie sheet lined with parchment paper. (At this point, can be frozen up to 2 weeks.)
5. Brush tops with oil. Bake until golden brown, about 16 minutes (longer if frozen). Let cool slightly and serve with warm marinara sauce.