01 -  Spread softened butter evenly over one side of each slice of bread. Sprinkle everything bagel seasoning on the buttered sides if desired. 
 02 -  Layer two slices of cheddar cheese between each pair of bread slices, ensuring buttered sides are facing outward. 
 03 -  Preheat the air fryer to 350°F (175°C) for 2 minutes. 
 04 -  Arrange the sandwiches in the air fryer basket in a single layer. Cook for 5 to 7 minutes, flipping once halfway, until the bread is golden and the cheese reaches optimum melt. 
 05 -  Remove from the air fryer and serve immediately, optionally paired with tomato soup for dipping.