This sandwich is so simple, that's I almost didn't share it at all. But, so much flavor! The crunchy bread, the melty cheese, the spicy chicken. It has all the things I love and it takes about zero seconds to throw together.
Heat a skillet over medium-low heat. Spray with non-stick cooking spray.
In a small bowl, toss the chicken in the buffalo sauce to coat.
Butter one side of each slice of bread. Place two slices butter side down on the skillet. Top each with half of the cheddar, followed by the chicken mixture, and then the mozzarella. Place the remaining slices of bread on top, butter side up.
Grill for 5 minutes or until the bottoms are golden brown (adjust heat if this is happening too quickly - you need time for the cheese to melt) and carefully flip. Continue cooking until cheese is melted and bottom is golden.