Lay slices of bread on a counter or cutting board. Place half the cheese on one slice. Layer the apples on top. Add the remaining cheese and top with the other slice of bread.
Heat a skillet over medium-high heat. Add butter. When melted, place sandwich in pan, and cook until golden on one side, 1 to 2 minutes. Use a spatula to flip the sandwich, cook until golden on the other side, 1 to 2 minutes, then transfer to a cutting board. Let cool for 1 minute, cut in half or into sticks and serve immediately.