01 - Preheat oven to 350°F or set a large skillet or griddle over medium heat.
02 - Using a serrated knife, slice the entire sheet of Hawaiian rolls horizontally in one piece without separating them. Place the bottom half on a baking sheet or flat work surface.
03 - Distribute the sliced cheddar and mozzarella evenly across the bottom half of the rolls, covering the entire surface. Place the top half of the rolls back over the cheese layer.
04 - In a small bowl, combine the softened butter with garlic powder and chopped parsley. Mix until well blended.
05 - Spread the butter mixture evenly over the top of the rolls using a pastry brush or the back of a spoon, ensuring full coverage.
06 - For oven method: Bake uncovered for 12 to 15 minutes until cheese is fully melted and tops are golden brown. For skillet method: Cut into individual rolls and grill each side for 2 to 3 minutes until golden with melted cheese.
07 - Remove from heat and let rest briefly. Separate into individual rolls and serve warm.