Prepare the Dough. Roll out the pizza dough on a floured surface into a large circle.
Prepare the Filling. In a bowl, mix mozzarella, ricotta, pepperoni, and vegetables. Add a spoonful of tomato sauce and a sprinkle of Italian seasoning.
Add the Filling. Place the filling mixture on one half of the dough circle, leaving a border around the edge.
Fold and Seal. Fold the dough over the filling to create a half-moon shape. Press the edges to seal, and use a fork to crimp the edges for a decorative touch.
Brush with Olive Oil. Brush the top of each calzone with olive oil for a golden finish.
Bake. Place the calzones on a baking sheet lined with parchment paper and bake for 15-20 minutes or until golden brown and crispy.