Heat a skillet over medium-high heat and cook the ground beef until fully browned, about 7–9 minutes. Drain excess fat.

Lower the heat to medium and season the beef with salt, pepper, garlic powder, and onion powder. Stir to combine and cook for 1 more minute.

While beef is cooking, butter one side of each bread slice.

On a clean surface, place one slice of bread buttered-side down. Layer with cheddar, beef, then mozzarella. Top with the second slice, buttered-side up.

Heat a clean skillet over medium heat. Toast the sandwich for 3–4 minutes per side, pressing lightly, until golden brown and cheese is melted.

Remove from heat, let it rest for a minute, then slice and serve warm.