In a spacious mixing bowl, combine the cooled mashed potatoes, shredded cheddar cheese, grated Parmesan cheese, and all-purpose flour. Mix thoroughly until the ingredients are well integrated and forms a cohesive mixture.
Carefully incorporate the beaten eggs, finely chopped green onions, garlic powder, black pepper, and salt into the mixture. Stir until you achieve a smooth, uniform consistency.
Cover the bowl tightly with plastic wrap and refrigerate the potato mixture for approximately 30 minutes. Chilling the mixture allows it to firm up, making it easier to handle during shaping.
In a deep frying pan, heat a sufficient amount of vegetable oil over medium heat. You should aim for enough oil to partially submerge the puff balls during frying.
Using a tablespoon, scoop out portions of the potato mixture and gently shape them into balls, around the size of a golf ball.
When the oil reaches the right temperature (you can check by dropping a small piece of the mixture into the oil; it should sizzle), carefully add the potato balls into the hot oil in small batches to avoid overcrowding.
Fry the cloud puffs until they turn a beautiful golden brown, approximately 3-4 minutes per side. Keep an eye on them to ensure even cooking.
Once cooked, use a slotted spoon to remove the puffs from the oil, placing them on a plate lined with paper towels to drain any excess oil.
Enjoy the cheesy cloud puffs while they are warm, served with a side of creamy sour cream or a tangy dipping sauce for an extra flavor kick.
Notes
Serve warm with sour cream or a tangy dipping sauce.