Spray or brush a 10-inch cast iron or non-stick skillet or a cake pan with oil.
Roll out the pizza dough into a 16 by 12 inch rectangle. If it's too difficult to roll, cover the dough with a kitchen towel to let it relax, wait five minutes or so, and then roll it out.
Layer the veggies over the dough, going all the way to the edges except one long seam where you will seal the dough. Scatter the mozzarella shreds, if using, over the veggies.
With the long side of the rectangle facing you, roll the dough gently -- like you would a jelly roll, until you have a long cylinder. Press in the seam along the long side to seal.
With a sharp knife, cut the cylinder into eight pieces. Place them in the skillet or baking pan. If veggies fall out as you lift the rolls into the pan, scatter them in the middle and over the top of the rolls. They'll look really pretty as they bake.
Cover with a kitchen towel and set aside in a warm place for an hour to rise.
Preheat the oven to 375 degrees Fahrenheit.
Bake the pizza rolls in the preheated oven for 35 minutes or until golden. Remove, cool on a rack for five minutes, then serve by themselves or with marinara on the side