01 - Using a sharp paring knife, carefully carve jack-o'-lantern shapes into 4 bread slices, creating triangles for eyes and nose and a zigzag mouth.
02 - Spread a thin, even layer of softened unsalted butter on one side of each bread slice.
03 - Place 4 uncut bread slices, buttered side down, on a clean work surface. Layer each with 2 slices of sharp cheddar cheese.
04 - Cover each prepared stack with a jack-o'-lantern cut-out bread slice, placing buttered side facing up to form the sandwich.
05 - Preheat a large skillet or griddle over medium heat. Cook sandwiches for 3 to 4 minutes per side, pressing gently, until bread is golden brown and cheese is fully melted.
06 - Serve sandwiches warm accompanied by ketchup or marinara sauce for dipping.