In a large mixing bowl, combine the mashed potatoes, all-purpose flour, Parmesan cheese, chopped fresh herbs, garlic powder, salt, and black pepper. Mix well until all the ingredients are thoroughly combined and the mixture holds together.
Take a small portion of the mashed potato mixture and roll it between your palms to form a ball. Repeat the process until all the mashed potato mixture is used, placing the formed balls on a baking sheet.
In a shallow dish, beat the eggs. Place the breadcrumbs in another shallow dish. Dip each mashed potato ball into the beaten eggs, ensuring it is coated all over. Then roll the ball in the breadcrumbs, pressing lightly to adhere the crumbs to the surface.
Heat vegetable oil in a deep skillet or frying pan over medium heat. Carefully place the coated mashed potato balls into the hot oil, working in batches if needed to avoid overcrowding the pan. Fry the balls until they turn golden brown and crispy on all sides, using tongs or a slotted spoon to gently flip them.
Once fried, remove the mashed potato balls from the oil and place them on a paper towel-lined plate to drain excess oil. Serve immediately with your favorite dipping sauce.