Set out two sheets of parchment paper.

In a large mixing bowl, combine ground beef, hamburger seasoning, seasoned salt, and garlic powder. Mix until just combined.

Divide the ground beef mixture into four equal portions (4 ounces each). Shape a portion into a loose ball and place it onto one of the sheets of parchment paper. Set the second sheet of parchment paper on top of the ball of meat. Using a rolling pin or your hand, press the meat into a thin, round patty about 5 inches in diameter. Set aside. Form the other three patties.

Preheat a large skillet over medium-high heat. When hot, cook the patties for 4-5 minutes per side, or until reaching the desired doneness. (Depending on the size of your skillet, you may have to work in batches.)

While the beef patties are grilling, spread ½ tablespoon of butter on the inside of each half of the hamburger buns, totaling 8 halves (4 buns).

Into a separate skillet over medium heat, place four buttered buns cut side down. Top each with 2 slices of cheese and the remaining buns, buttered side up. Lightly press or smash the grilled cheese buns to reduce their thickness. Once golden brown and toasted on the bottom, flip the buns and cook the opposite side.

Top one grilled cheese bun with a hamburger patty, your choice of toppings, another hamburger patty, and finally, a grilled cheese bun. Repeat for the second sandwich. Serve immediately.