Heat the olive oil in a skillet over medium heat. Add the ground beef, breaking it up with a spatula. Season with garlic powder, onion powder, salt, and pepper. Cook until the beef is browned and cooked through, about 7–8 minutes. Drain any excess fat and set aside.
Spread a thin layer of butter on one side of each bread slice. This will ensure a golden, crispy exterior when grilled. Place the slices butter-side-down on a clean surface, then add a slice of cheddar cheese on two of the bread slices.
Evenly distribute the cooked ground beef over the cheese slices. Top with the remaining slices of cheddar cheese, then place the other bread slices on top, butter-side-up, to complete your sandwiches.
Heat a clean skillet or griddle over medium heat. Place the sandwiches in the skillet and cook for 3–4 minutes on each side, pressing gently with a spatula, until the bread is golden brown and the cheese is melted. Adjust the heat as needed to prevent burning.
Remove the sandwiches from the skillet and let them cool for a minute before slicing in half. Serve with your favorite sides or a simple salad for a satisfying meal.