01 - Spread softened butter evenly on one side of each bread slice, ensuring complete coverage to the edges.
02 - Place two bread slices buttered side down on work surface. Layer two cheese slices on each, then top with remaining bread slices, buttered side up.
03 - Preheat a large skillet or griddle over medium heat for 2-3 minutes until hot but not smoking.
04 - Place sandwiches in hot skillet. Cook for 3-4 minutes, pressing gently with spatula, until bottom is golden brown and cheese begins to melt.
05 - Flip sandwiches carefully. Cook another 3-4 minutes, pressing gently, until both sides are golden brown and cheese is completely melted.
06 - Transfer sandwiches to cutting board. Let rest 1 minute, then cut diagonally into halves or quarters. Serve immediately while hot.