01 - Using a sharp paring knife, cut jack-o'-lantern faces—triangles for eyes and nose, and a zigzag mouth—into 4 slices of bread.
02 - Spread a thin, even layer of softened unsalted butter on one side of each bread slice.
03 - Arrange 4 plain bread slices, buttered side down, on a clean surface. Place 2 slices of cheddar cheese on each.
04 - Top each cheese-covered bread slice with a jack-o'-lantern cut-out slice, buttered side up, aligning edges to form sandwiches.
05 - Warm a large skillet or griddle over medium heat. Grill sandwiches for 3 to 4 minutes per side, pressing gently, until bread is golden brown and cheese is melted.
06 - Serve sandwiches warm, accompanied by ketchup or marinara sauce for dipping.