1. Preheat oven to 400F. In medium bowl, combine ricotta, mozzarella, spinach, salt and pepper.
2. On a lightly floured work surface, roll dough out into a 15-inch circle. Spread cheese mixture over one half of the circle, to within 1 inch of the edge. Lift the other side of dough and fold it over, forming a half-moon. Pinch the edges together to seal.
3. Transfer to a large baking sheet and sprinkle the top with the Parmesan. Bake until puffed up and golden brown, about 15-20 min. Let stand for 5 min before slicing crosswise into thick slices. Serve with spaghetti sauce on the side.
Note: I used Pillsbury's Pizza Dough in the "roll" can and just unfolded the dough, rather than rolling out dough. Also, I've added 1/3 cup chopped pepperoni pieces to the spinach mixture and it was good!
From Robin Miller's Robin To The Rescue.