Preheat the oven to 400°F. Line a baking sheet with foil. Spray with nonstick spray.
Unwrap the string cheese and cut each one into thirds.
Stir together the oregano, garlic powder, and cheese.
Open the pizza crust and lay it out on a pan. Cut it into 24 even pieces.
Place a piece of cheese in the center of each one. Roll the dough up tightly, pinching the seams tightly. Place on the prepared pan.
Brush each dough roll with butter. Sprinkle with the cheese mixture. Press a pepperoni into the top of each pizza bite. Bake for 10-12 minutes.
Serve immediately with pizza sauce, if desired.
