Place the pizza dough in an oiled bowl and cover with plastic wrap. Let the dough come to room temperature. (The longer you let the dough sit, the puffier it will get.)
Preheat oven to 500 degrees.
Stretch and press the pizza dough to fit the cast iron pan, pressing it slightly up onto the sides of the pan.
Spread the pizza sauce onto the dough. Sprinkle the cheese evenly across the pizza, followed by the pepperoni, if desired.
Bake for 16-18 minutes. Slide the pizza onto a cutting board before slicing.