Preheat your oven to 220 C. Lightly grease with a butter a pie baking dish.
Mix together the tomato sauce, cheese, and pepperoni in a small bowl.
Shape the pizza dough into a large rectangle, and with a sharp knife or dough cutter, cut into 24 even squares.
Add a small spoon of filling to a square, then pull the corners up to the top and pinch together to seal, to make a round ball, place the ball in the pie dish seam side down. Repeat for the all the squares.
Once all the balls are in the pie dish, brush on the melted butter.
Bake for 15 to 20 minutes or until the top is golden brown. Serve with additional tomato sauce for dipping, enjoy.