Butter one side of 8 slices of bread and place butter-side down on a baking tray. Arrange cheese on each slice of bread. Spread butter on 8 remaining slices of bread and place them buttered-side up on top of the cheese.
Bake in preheated oven for 6 to 8 minutes. Flip the sandwiches and bake an additional 6 to 8 minutes or until golden brown.