The word calzone means "pant leg" in Italian. How hand-held pizza relates to a pant leg is not clear to me. The exact origins of calzones are unclear, some believe that calzones may have originated during the medieval Arab period, and are related to sanbusaks, fried meat-filled pastries. Today, calzones are most commonly associated with Naples, Italy where the sandwich-sized turnovers are often sold at Italian lunch counters or by street vendors because they are easy to eat while standing or walking.
As a general rule, calzones are usually stuffed with regional cheeses such as ricotta, mozzarella, Parmesan, or Provolone. The dough is folded into a half-moon shape with the edges sealed. After cooking, calzones are commonly served with marinara sauce. For me, a true calzone is pizza dough filled with a mixture of spinach and ricotta with mozzarella. The guys tend to want meat in theirs which is certainly an option.
One batch Pizza Dough
1 cup cooked spinach, chopped
1/2 cup Parmesan cheese, freshly grated
1 cup ricotta cheese
Pinch of nutmeg
Kosher salt and freshly ground pepper
1/2 cup mozzarella cheese, grated
Extra flour for dusting
For the spinach, we are usually lucky to have leftovers that has already been sautéed with garlic and a little crushed red pepper. If you are using frozen spinach, you may choose to punch it up with some garlic and spice. Which ever you are using, be sure to squeeze as much liquid from the greens as possible. Transfer the spinach to a bowl, add the Parmesan, and ricotta cheeses and mix well. Season with nutmeg, salt and pepper.
Position racks in the center and lower third of an oven and preheat to 500°F. If you are using a pizza stone be sure to place it in the oven so it gets hot too. Divide the pizza dough into 3 equal portions, and shape each portion into a ball. Place the balls on a work surface and cover with a kitchen towel. Place 1 ball on a floured work surface, and roll out into a round 7 inches in diameter.
Sprinkle some mozzarella on one half of each round leaving a half-inch border and top with a scoop of the spinach ricotta mixture. Sprinkle some more mozzarella over the top before folding the top half of the dough over and crimping the edges to seal. It helps to moisten the edges with a little warm water to encourage the dough to seal properly.
Slide the calzones onto your pizza stone or place on a baking sheet and place in the preheated oven. Bake for about 20 minutes, until golden brown and puffed. About half way through baking you can poke a hole in the top to allow some of the steam escape if it looks like it might burst open. If the dough looks really dry and floury, you can brush the top with olive oil. This will help the top to brown nicely as well. Transfer to wire racks and let cool for 5-10 minutes. Serve warm with tomato sauce.