¾ cup butter or margarine
3 cups sugar
1 can (5 oz.) evaporated milk
1 package (12 oz.) semi-sweet chocolate chips
1 jar (7 oz.) marshmallow cream
1 tsp. vanilla

Lightly grease a 13×9 inch or 9-inch square pan. Mix butter, sugar and milk in a heavy 2 ½ -3-quart saucepan; bring to a full rolling boil on medium heat, stirring constantly.  Continue boiling for 5 minutes on medium heat or until the candy thermometer reaches 234⁰, stirring constantly to prevent scorching. Remove from heat and gradually stir in chocolate chips until melted. Add remaining ingredients and mix well. Pour into the prepared pan. Cool at room temperature; cut into thin squares.