Heat a skillet over medium heat and melt one tablespoon of butter on the skillet.
While the skillet heats, assemble the sandwich. Take two slices of sourdough bread and spread pizza sauce evenly on each slice.
On one slice, layer half of the shredded mozzarella cheese, followed by the sliced pepperoni, and sprinkle half of the grated Parmesan on top.
Add the dried oregano and garlic powder, then top with the remaining mozzarella cheese. Place the second slice of bread on top to create a sandwich.
Carefully place the sandwich in the hot skillet and toast until the bread is golden brown and the cheese starts to melt, about 3-4 minutes.
While the first side is cooking, spread a thin layer of the remaining butter on the top slice of the sandwich.
Flip the sandwich carefully and cook the other side for another 3-4 minutes until it's golden and crispy.
Once cooked, remove the sandwich from the skillet. Let it sit for a minute before slicing it in half for easier handling.
Serve warm with extra pizza sauce on the side for dipping.
Notes
Serve the pizza grilled cheese on a cutting board, garnished with a sprinkle of fresh parsley for a pop of color. Use a small bowl to hold the extra pizza sauce for dipping!