Prepare the Mashed Potatoes

1. Make Sure They’re Cold: If you’re using leftover mashed potatoes, ensure they are cooled. If you’re making fresh mashed potatoes, allow them to cool before using. This helps the puffs hold their shape better.

Mix the Ingredients

1. Combine the Ingredients: In a large mixing bowl, combine the cold mashed potatoes, shredded cheddar cheese, Parmesan cheese, sour cream (or Greek yogurt), green onions, garlic powder, onion powder, salt, and pepper. Mix until well combined.
2. Add the Egg: Stir in the beaten egg to bind the mixture together. This will help the puffs hold their shape while baking.

Shape the Puffs

1. Form the Puffs: Using your hands or a spoon, form the mashed potato mixture into small, round balls (about 1-1 1/2 inches in diameter). Place them on a parchment-lined baking sheet.
2. Coat with Breadcrumbs: Roll each puff in the breadcrumbs to coat the outside, ensuring they are fully covered. This will help them achieve that crispy, golden texture when baked.

Bake the Puffs

1. Preheat the Oven: Preheat your oven to 400°F (200°C).
2. Grease the Baking Sheet: Lightly grease the baking sheet with olive oil spray or brush it with melted butter to prevent the puffs from sticking.
3. Bake: Place the mashed potato puffs on the prepared baking sheet and bake for 20-25 minutes, or until they are golden brown and crispy on the outside. You can flip them halfway through to ensure even cooking.

Serve

1. Cool Slightly: Let the puffs cool for a few minutes before serving. Serve warm, with your favorite dipping sauces or alongside a main dish.