Preheat the oven to 400 degrees F (200 degrees C).
In a large mixing bowl, combine the flour, baking powder, salt, garlic powder, and black pepper.
In a separate bowl, whisk together the melted butter and milk until well combined.
Pour the wet ingredients into the dry ingredients and mix until just combined. Do not overmix.
Fold in the shredded mozzarella cheese, Parmesan cheese, and chopped parsley.
Using a tablespoon, scoop out dough and place a small piece of mozzarella cheese in the center of each scoop.
Form the dough around the cheese to enclose it and shape it into a ball.
Place the biscuit bombs on a baking sheet lined with parchment paper, spacing them about 2 inches apart.
Bake in the preheated oven for 15-20 minutes or until golden brown.
Remove from the oven and let cool slightly before serving.