Preheat your oven to 350°F (175°C).

Slice the pack of Hawaiian rolls in half horizontally without cutting all the way through.

Spread softened butter onto the cut sides of both halves of the Hawaiian rolls.

Sprinkle garlic powder over the buttered surfaces.

Layer both the shredded cheddar and mozzarella cheese on the bottom half of the sliced Hawaiian rolls.

Place the top half of the Hawaiian rolls back onto the cheese-covered bottom half.

Wrap the entire sandwich tightly in aluminum foil.

Bake in the preheated oven for about 15-20 minutes.

Unwrap the foil and return the rolls to the oven for an additional 5 minutes.

Let cool briefly before slicing into bite-sized pieces.