Panuozzo or panozzo was invented in 1983 by Giuseppe Mascolo of Gragnano, who wanted to make something his kids would like, so took some pizza dough, stretched it out in a long oval, baked it, cut it open and filled with mozzarella and pancetto, then briefly baked it again until it was crispy. His 13-year old daughter suggested calling it panuozzo and the name stuck. In 1996, the family trademarked the name.
Panuozzi are a popular street food: friarielli and sausage are a popular filling, but you can even find them with steak and potatoes.
Image by Mess, Creative Commons License