Preheat oven to 350°.
Layer graham crackers on the bottom of a sprayed 9 X 13 inch pan.
Sprinkle marshmallows onto graham crackers.
Sprinkle chocolate chips onto marshmallows.
Sprinkle cashews onto chips.

In a medium saucepan, melt butter, add brown sugar and cook until sugar dissolves
Remove from heat, add vanilla.
Bake 10-12 minutes until marshmallows are puffy and lightly browned.
Cool completely before cutting into bars.