Preheat the oven to 350°F. Spray a 7x11-inch baking dish with nonstick cooking spray.
In a small bowl, mix together the melted butter, garlic salt, Italian seasoning, and parmesan cheese. Set aside.
Split your rolls in half horizontally and place the bottom halves in the baking dish.
Top the bottom halves of the buns with 6 of the mozzarella cheese slices. Follow with a layer of the pepperoni slices, pizza sauce, and the remaining mozzarella cheese slices.
Place the top halves of the buns on top and brush the top of the rolls with the melted butter mixture.
Cover the dish with aluminum foil and bake for 15 minutes, or until the cheese is hot and bubbly.
Remove foil and bake for an additional 5 minutes (or until the tops of the sliders turn a golden brown).
Remove from oven, slice, and serve!
