Preheat oven to 350°F (180°C) and lightly coat a 9×13-inch baking dish with cooking spray.
Slice the entire sheet of rolls horizontally. Place the bottom layer in the baking dish, cut side up.
12 mini rolls
In a bowl, combine the mozzarella, Parmesan, red pepper flakes, and half of the oregano.
12 ounces mozzarella cheese, ⅓ cup freshly grated Parmesan cheese, ½ teaspoon red pepper flakes, 1¼ teaspoons dried oregano
Spread half of the pizza sauce over the bottom rolls. Add half the cheese mixture. Layer the pepperoni evenly. Top with the remaining cheese mixture.
1 14-ounce jar pizza sauce, 6 ounces sliced pepperoni
Place the top half of the rolls over the filling. Cover loosely with foil and bake for 15 minutes.
Stir together the melted butter, garlic, and remaining oregano.
4 tablespoons salted butter, 2 cloves garlic
Remove the foil, brush the rolls with the garlic butter, and bake uncovered for about 10 minutes, or until golden and melty.
Warm the remaining pizza sauce in a small saucepan. Serve sliders hot with extra Parmesan and warm sauce on the side.