Melt the butter over low heat in a small saucepot, then add the oregano, garlic powder and salt. Mix together and set aside to cool.
½ teaspoon garlic powder, 1 teaspoon dried oregano, ½ teaspoon kosher salt, 4 tablespoons unsalted butter
Lay out a large rectangle of plastic wrap on the counter or a large cutting board, then unroll the dough onto the middle of the plastic.
1 can crescent roll dough
Reserve about a ¼ cup of the cheese and set aside for topping the rolls later. Sprinkle the rest evenly over the top of the dough, leaving a ½ inch strip along one side, which will be used to seal everything up.
8 ounces shredded mozzarella cheese
Layer the pepperoni evenly over the top of the cheese.
6 ounces sliced pepperoni
Begin rolling the dough up along the long edge into a log, using the plastic wrap to help guide it along the way. Moisten the edge of the dough that was left bare with a little water, then finish rolling into an even log, pinching along the seam to seal completely.
Wrap tightly in the plastic wrap and put in the freezer until it has firmed up enough to slice cleanly, about 20 minutes.
While the dough is chilling in the freezer, preheat the oven to 375 F.
Once the dough has firmed up, cut into 8 equal slices and arrange on a parchment lined sheet pan, leaving plenty of space in between for them to expand.
Using a pastry brush, brush top of the rolls with the garlic herb butter, then sprinkle the top with the reserved cheese.
Bake for 12 - 15 minutes until they are done throughout and a golden brown color.
While still warm, brush the tops again with more herb butter.