01 - Preheat your waffle iron to medium-high heat setting.
02 - Grate the peeled russet potatoes using a box grater. Place the grated potatoes in a clean kitchen towel and squeeze out as much liquid as possible until dry.
03 - In a large bowl, combine the grated potatoes, grated yellow onion, egg, flour, garlic powder, salt, and black pepper. Mix until thoroughly incorporated and evenly distributed.
04 - Stir the melted unsalted butter into the potato mixture until well combined.
05 - Lightly grease both sides of the preheated waffle iron with vegetable oil or nonstick cooking spray.
06 - Spread a generous, even layer of the potato mixture onto the waffle iron without overfilling. Close the lid and cook for 10–12 minutes until deeply golden and crispy throughout.
07 - Carefully remove the cooked hashbrowns using a spatula. Repeat the cooking process with the remaining potato mixture.
08 - Serve immediately while hot and crispy. Optionally garnish with fresh chopped herbs or accompany with your preferred breakfast toppings.