Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper and set aside.
On a lightly floured surface, roll the pizza dough into a 12x10 inch rectangle.
Spread pizza sauce evenly over the dough, leaving a 1/2 inch border all around.
Sprinkle shredded mozzarella evenly over the sauce, then layer pepperoni slices on top. Sprinkle garlic powder and Italian seasoning over the filling.
Starting from the long side, roll the dough tightly into a log. Pinch the seams to seal and tuck the ends under.
Place the log seam-side down on the prepared baking sheet. Brush with melted butter (or egg wash for a shinier crust) and sprinkle with grated Parmesan and a little extra Italian seasoning.
Bake for 22 to 25 minutes, until golden brown and the cheese is melted. Let rest 5 minutes before slicing.
Slice into 8 pieces and serve warm with extra pizza sauce for dipping.
Notes
Store leftovers in the refrigerator for up to 3 days. Reheat in a 350°F oven for 8–10 minutes for best texture.