01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - Without separating the rolls, cut the entire block horizontally to create top and bottom layers.
03 - Place the bottom half onto the prepared baking sheet.
04 - Evenly layer the mozzarella and cheddar cheeses over the bottom half of the rolls.
05 - Place the top half of the rolls over the cheese layer.
06 - In a small bowl, mix the melted butter with garlic powder.
07 - Brush the butter mixture liberally over the tops of the rolls.
08 - Sprinkle with chopped parsley and Parmesan cheese, if using.
09 - Bake for 12-15 minutes, or until the cheese is melted and the tops are golden brown.
10 - Remove from oven. Let cool for 2 minutes, then separate into individual rolls using a sharp knife. Serve warm.