Divide the ground beef into 8 equal parts and shape into balls. Place each ball on a plate or tray and refrigerate.

In a small bowl, combine the salt, MSG, black pepper, and garlic powder. Transfer to a small jar and set aside.

In another small bowl, mix the mayonnaise and ketchup until even in color. Cover and refrigerate.

Preheat a griddle or pan on high heat for about 1 minute. Add butter and toast the burger buns. Set aside.

Place the beef balls on the griddle at least 4 inches apart. Cover each ball with parchment paper and smash for 5 seconds.

Cook for 1 minute and 15 seconds, then season each burger with about ? teaspoon of the seasoning. Flip the burgers and finish cooking.

Add the cheese 10 seconds before removing burgers from heat.

Stack 2 burger patties in each burger bun. Add about a tablespoon of the sauce per burger.