Divide ground beef into 2 to 3 ounce balls, roughly the size of a golf ball. Don't pack them tight, just loosely form them. Season the outside of each ball lightly with salt and pepper.
Preheat your Blackstone griddle to 400 to 425 degrees for at least 10 minutes until very hot.
Add a small amount of oil to the griddle surface to create a thin layer where burgers will go.
Place beef balls directly on the hot oiled surface, giving them a couple inches of space between each one.
Immediately press down firmly with burger press to smash patties to about 0.25 inch thick. Apply solid pressure for 3 to 5 seconds, then lift straight up. Do not twist or wiggle the press.
Let burgers cook undisturbed for 2 to 3 minutes until edges are deep brown and crispy and the top surface looks cooked about halfway up.
Flip burgers with a large sturdy spatula. Immediately add a slice of cheese to each patty.
Cook second side for 60 to 90 seconds to warm through and melt cheese.
While burgers finish, butter the buns and place face-down on griddle. Toast for about 30 seconds until golden.
Remove everything from griddle. Assemble burgers with bottom bun, patty with cheese, toppings, condiments, and top bun. Serve immediately.