Melt together the chocolate and butterscotch chips and the peanut butter. Pour half of this mixture into a large buttered jelly-roll pan.
Mix butter, milk and dry pudding together. Boil for 1 minute. Add flavoring and powdered sugar. Spoon over first layer; chill.
Add nuts to redessertsing chocolate mixture; spoon over second layer. Chill. Cut into small pieces. Keep refrigerated. "Very rich bars!"