In a large bowl, mix the cooled rice with Parmesan cheese, 1 egg, salt, and black pepper. Combine until the mixture holds together.

Take a small handful of the rice mixture, flatten it in your palm, place a piece of mozzarella in the center, and shape it into a ball. Repeat with the remaining mixture.

Roll each rice ball in flour, then dip into the beaten egg, and coat with breadcrumbs.

Heat vegetable oil in a deep pan over medium heat. Fry the rice balls in batches until golden brown and crispy, about 3-4 minutes per batch. Drain on paper towels.

Serve warm as a snack or appetizer.