Grease a 8x8 baking dish with butter or cooking spray.

In a medium suacepan on medium low heat, add the butter, peanut butter, and butterscotch chips.

Stir and let everything melt until smooth, remove from heat and stir in vanilla and a pinch of salt. Let this cool to room temperature.

When cooled, stir in the marshmallows.

Pour into the prepared baking dish and spread out evenly.

Place in the fridge to cool and set. Cut into 2 inch squares, serve and enjoy.