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 all ingredients are evenly distributed.
04 - Pour the melted butter into the potato mixture and stir thoroughly to incorporate.
05 - Lightly grease both sides of the preheated waffle iron with vegetable oil or nonstick cooking spray.
06 - Spread an even layer of the potato mixture onto the waffle iron, being careful not to overfill. Close the lid and cook for 10 to 12 minutes until deeply golden brown and crispy.
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 herbs or accompany with your preferred breakfast toppings.