Microwave until these ingredients are melted, stirring every 30 seconds:

 4 cups minature marshmallows
 1/4 cup butter
 1 bag of butterscotch morsels

Add to the melted mixture, and mix together:

 4 cups Rice Krispies

Spread onto a greased baking pan.
Let cool for about 30 minutes.
Cut into bars or squares.