Lay out the bread slices on a clean work surface.
Place a slice of cheese on one bread slice.
Top the cheese with the other bread slice to form a sandwich.
Spread a thin layer of softened butter or margarine on the outside of both sides of the sandwich. Make sure to coat the entire surface.
Preheat a skillet or frying pan over medium-low heat.
Place the buttered sandwich in the preheated skillet and cook for 2-3 minutes or until the bottom side turns golden and crispy.
Carefully flip the sandwich with a spatula and cook the other side for an additional 2-3 minutes, or until it turns golden and the cheese inside starts to melt.
Once both sides are nicely toasted and the cheese is melted, remove the sandwich from the skillet and transfer it to a cutting board.
Let the sandwich cool for a moment, then slice it diagonally into halves or quarters.
Serve the Classic Grilled Cheese Sandwich immediately while it's still warm and enjoy the ooey-gooey goodness!
