Proof the yeast: combine warm water and sugar, add yeast, and let it sit for 5-10 minutes until bubbly.
In a large mixing bowl, combine the flour, salt, garlic powder, and melted butter.
Pour the yeast mixture into the dry ingredients and mix until a dough forms.
Knead the dough on a floured surface for about 5-8 minutes until smooth and elastic.
Place the dough in a greased bowl, cover it, and let it rise in a warm area until doubled in size, about 1 hour.
After rising, punch down the dough to release air, then add mozzarella and Parmesan cheese, kneading briefly to combine.
Shape the dough into 12 equal balls and place them in a greased baking dish, leaving some space in between.
Cover with a towel and let them rise until doubled, about 30 minutes.
Preheat the oven to 375°F (190°C).
Bake the rolls for 20-25 minutes, or until golden brown.
Remove from the oven, brush with melted butter, and sprinkle with parsley if desired.