01 - Preheat oven to 350°F. Line a rimmed baking sheet with parchment paper.
02 - Using a serrated bread knife, slice the entire slab of Hawaiian rolls in half horizontally, keeping them connected as one piece. Do not separate individual rolls.
03 - Place the bottom half of the roll slab onto the prepared baking sheet. Distribute cheddar and mozzarella slices evenly across the surface, covering the bread completely.
04 - Set the top half of the rolls back in place over the cheese layer, pressing down gently to create a unified sandwich slab.
05 - In a small mixing bowl, whisk together the melted butter, garlic powder, dried parsley, and sea salt until well combined.
06 - Using a pastry brush, generously coat the tops and sides of the roll slab with the garlic butter mixture, ensuring even coverage.
07 - Loosely tent the baking sheet with aluminum foil and bake for 10 minutes, allowing the cheese to begin melting.
08 - Remove the foil and continue baking for 5 more minutes until the cheese is fully melted and the roll tops are golden brown and slightly crisp.
09 - Remove from the oven and allow to rest for 2 to 3 minutes. Use a sharp knife to separate into 12 individual mini sandwiches. Serve warm.