01 - Peel the russet potatoes and grate them using a box grater. Gather the grated potatoes in a clean kitchen towel and wring out firmly to remove as much moisture as possible. Transfer the dried potatoes to a mixing bowl.
02 - Add the melted butter, vegetable oil, garlic powder, onion powder, and a generous pinch of salt and pepper to the grated potatoes. Toss everything together until evenly coated.
03 - Heat a large nonstick skillet or flat griddle over medium-high heat. Divide the potato mixture into 4 equal portions. Press each portion into a thin patty roughly 4 inches in diameter. Cook for 3 to 4 minutes per side until deeply golden and crisp on both edges. Remove and set aside in a warm spot.
04 - Gently shape the ground beef into 4 loose balls, being careful not to overwork the meat. Wipe the skillet clean and return it to high heat. Once the surface is ripping hot, set the beef balls onto the skillet and immediately smash each one flat with a heavy-duty spatula or burger press. Season the top generously with salt and pepper.
05 - Let the patties cook undisturbed for 2 to 3 minutes until the bottoms develop a dark crust and the edges turn crispy. Flip each patty, lay a slice of cheddar on top, and continue cooking for another 1 to 2 minutes until the cheese is fully melted.
06 - Spread burger sauce generously on the bottom half of each toasted bun. Stack a lettuce leaf, a tomato slice, and a few red onion rings on top of the sauce. Place a hash brown patty on the vegetables, then set the cheesy smashed burger over it. Layer pickle slices on the patty and crown with the top bun.
07 - Plate the assembled burgers right away while the patties are still hot and the hash browns retain their crunch. Pair with crispy fries or a simple side salad if desired.