Combine butterscotch chips and sweetened condensed milk. Add marshmallows in top of double boiler. Place over boiling water and stir occasionally, until melted and smooth. Remove from heat. Stir in peanut butter, vanilla and salt. Pour into buttered 8-inch square pan. Chill until almost firm. Cut into squares. Press quarter piece of cherry on each piece. Makes 2 1/4 pounds.