How to Make It
Preheat a waffle iron with 4 compartments to HIGH.
Place a paper towel on a microwave-safe plate. Arrange bacon on paper towel; cover with an additional paper towel. Microwave bacon at HIGH for 4 minutes or until done.
Combine mayonnaise and mustard in a small bowl. Spread about 1 1/4 teaspoons mayonnaise mixture over each bread slice. Divide bacon, turkey, apple slices, and cheese evenly among 4 bread slices; top with remaining bread slices, spread side down. Lightly coat both sides of sandwiches with cooking spray. Place 1 sandwich in each compartment of waffle iron; close waffle iron firmly on sandwiches. Place a heavy skillet on top of waffle iron to help flatten sandwiches evenly. Cook 3 to 4 minutes or until golden brown and cheese melts.