Don’t pull the rolls apart. Cut them in half horizontally. Place the top halves aside and bottom halves in the baking pan (coat the bottom of the pan with cooking spray).
Spread ½ cup of the pizza sauce over the bottom halves of the sliders. Sprinkle ¾ cup mozzarella cheese next. Then layer with pepperoni. Sprinkle the rest of the mozzarella for the next layer. Then add grated Parmesan cheese and oregano. Finally drizzle the rest of the pizza sauce over the cheese layers. Then, top with the upper halves of the sliders.
In a bowl: whisk melted butter, garlic, parsley until well mixed. Then brush or spread the butter mixture over the top of the rolls
Bake for 15-20 minutes or until the cheese has melted.