In a large mixing bowl, cream together the butter, brown sugar, and granulated sugar.
Add the flour, egg, apple butter, baking soda, nutmeg, vanilla extract, and raisins. Mix well.
Spray a thin, air-fryer-safe baking pan with olive oil or cooking spray.
Spread the batter into the pan in an even layer.
Place the pan in the air fryer and cook at 320°F for 12–15 minutes, until a toothpick inserted in the center comes out clean.
Let cool completely. In a small bowl, whisk together the powdered sugar and milk until it reaches the consistency of glue.
Drizzle the icing over the cooled bars.
Let the glaze set for a few minutes, then slice, serve, and enjoy!