Preheat the oven to 450 degrees . Sprinkle the cornmeal on a large cutting board and roll out the pizza dough to a 10-by-14-inch rectangle. Using a pizza wheel or large knife, cut into four 5-by-7-inch rectangles.
Working with 1 sheet at a time, place a rectangle so the long side is facing you. Spoon one-quarter of the chopped hot dogs onto the center of the rectangle, leaving a 1-inch border around the filling. Top the hot dogs with 1 tablespoon tomato sauce and 4 tablespoons shredded mozzarella. Moisten the edge of the dough all around and fold the rectangle in half lengthwise over the filling. Pinch the edges together to secure. Set on a parchment-paper-lined baking sheet. Repeat with the remaining dough rectangles, hot dogs, sauce and cheese. Cut 2 or 3 small vents in the top of each pocket. Bake until browned and bubbling, about 15 minutes. Let stand for 10 minutes before serving.