Divide ground beef into four equal portions (about 2 ounces each) - don't shape into patties, just loose balls. Season each portion generously with salt, black pepper, garlic powder, and onion powder.

Butter one side of each bread slice evenly from edge to edge. Set up assembly line with seasoned meat balls, buttered bread, cheese slices, and a sturdy spatula. Have a second spatula or heavy implement ready for smashing.

Heat a large skillet or griddle over medium-high heat to about 400°F. Place two slices of bread butter-side down in the pan.

Immediately place one portion of seasoned beef onto the center of each bread slice while in the pan. Press down HARD on the meat using spatula and heavy implement, smashing as thin as possible. Hold for about 10 seconds until meat spreads to nearly cover the entire bread slice.

Let the meat cook undisturbed for 2-3 minutes until edges turn deeply brown and crispy with lacy, caramelized appearance.

Carefully flip the entire bread-and-meat unit over using spatula. Let cook for about 1 minute to finish cooking the meat while unbuttered side of bread toasts.

Place cheese slices directly onto the cooked meat. Reduce heat to medium-low.

Take remaining two bread slices (buttered side facing up) and place directly on top of cheese, creating a sandwich. Press down gently.

After about 2 minutes, when bottom bread is deep golden brown and crispy, flip the entire sandwich. Cook for another 2-3 minutes until final side achieves perfect golden-brown color. Press down gently with spatula occasionally.

Remove from heat and let rest on cutting board for about 1 minute to allow cheese to set slightly.

Slice diagonally with sharp knife and serve immediately while hot.