In a saucepan combine & boil butter, milk, sugar & salt. Cook for 4-5 minutes. Remove from heat & stir in remaining ingredients. Stir until marhsmallows are blended (apprx. 1 minute).
Pour into greased 9x13 inch pan and cool in refrigerator.
Cut into small pieces. Serve cold. Keep in airtight container between sheets of waxed paper.