Soften butter. It can also be melted if preferred.Line sheet pans with parchment. Butter 24 slices of bread per sheet pan, 1 tsp per slice. cut cheese using slicer to 2 oz slices.
Place 24 slices of bread butter side down on parchment. Place 1 (2 oz) slice of cheese on each piece of bread. Spread the rest of the softened or melted butter on the outside of top piece of bread, 1 tsp per slice. Wrap sheet pans with plastic film tightly to hold sandwiches in place. Do not use bags. Label, date, refrigerate until transport.
Refrigerate until morning of service. Preheat oven to 350 degrees. Uncover sandwiches. Bake uncovered in oven about 8-10 minutes, until cheese is melted and bread is toasted golden brown. Keep warm until service. Cut sandwich in half, serve two halves per student.
