01 - Peel the russet potatoes and grate them using a box grater. Gather the grated potatoes in a clean kitchen towel and squeeze firmly to extract as much moisture as possible. Transfer the dried potatoes to a mixing bowl.
02 - Add the melted butter, vegetable oil, garlic powder, onion powder, salt, and pepper to the grated potatoes. Toss until the seasoning is evenly distributed throughout the mixture.
03 - Heat a large nonstick skillet or griddle over medium-high heat. Divide the potato mixture into 4 equal portions. Press each portion into a thin patty about 4 inches in diameter. Cook for 3 to 4 minutes per side until golden brown and crispy. Remove from the pan and keep warm.
04 - Gently shape the ground beef into 4 loose balls, being careful not to overwork the meat. Heat the skillet or griddle over high heat. Once the surface is very hot, place the beef balls on the pan and immediately smash each one flat with a heavy-duty spatula or burger press. Season generously with salt and pepper.
05 - Cook the smashed patties for 2 to 3 minutes until the bottoms are deeply browned and the edges are crispy. Flip each patty, immediately top with a slice of cheddar cheese, and cook for 1 to 2 additional minutes until the cheese is fully melted.
06 - Spread burger sauce on the bottom half of each toasted bun. Layer on a lettuce leaf, a tomato slice, and a few rings of red onion. Place a crispy hash brown patty on top, followed by the cheesy smash burger. Add pickle slices and crown with the top bun.
07 - Serve immediately while the hash browns are still crispy and the burger is hot and juicy.