Make the Garlic Butter: In a small bowl, mix together the softened butter, minced garlic, and chopped parsley (if using) until well combined. Set aside.

Prepare the Bread: Lay the four slices of bread on a chopping board. Spread the garlic butter evenly over one side of each slice. This buttered side will be the outside of your sandwiches.

Assemble the First Layer: Flip two of the bread slices over (buttered-side down). Spread half of the pizza sauce on each of the unbuttered sides. Sprinkle with the dried oregano and a pinch of black pepper.

Add the Cheese and Pepperoni: Divide the grated mozzarella and cheddar between the two sauce-covered slices, creating an even layer. Arrange the pepperoni slices on top of the cheese.

Close the Sandwiches: Place the remaining two slices of bread on top, buttered-side up, to close the sandwiches. Gently press down.

Cook the Sandwiches: Heat a large, non-stick frying pan over a low-to-medium heat. Carefully place the sandwiches in the pan. You may need to cook them one at a time depending on the size of your pan.

Grill to Perfection: Cook for 4-5 minutes on the first side, until the bread is a deep golden brown. I find that covering the pan with a lid during this stage helps trap steam and melt the cheese more effectively.

Flip and Finish: Carefully flip the sandwiches using a spatula and cook for another 4-5 minutes on the other side, until equally golden and the cheese is completely melted and oozing at the sides.

Rest and Serve: Transfer the pizza grilled cheese to a cutting board and let it rest for a minute. This allows the cheese to set slightly, so it doesn't all escape when you slice it. Cut in half and serve immediately.