My friend Marian shared this recipe with me recently when I visited her in Pennsylvania. Her family members have been making it for many years,
In a large heavy saucepan, combine sugar or sugar substitute and milk; bring mixture to a boil over moderate to high heat. Continue boiling until a candy thermometer inserted into the mixture registers 238 degrees (mixture forms a soft ball when dropped into cold water). Remove form heat; stir in marshmallows, butter, and crushed graham crackers, stirring until butter and marshmallows have melted.
Drop graham cracker mixture by rounded teaspoonfuls onto wax paper. Allow cookies to cool thoroughly and become firm. Store in an airtight container in a cool dry area.
Variation: Omit butter or margarine; add ½ cup creamy or crunch-style peanut butter with the graham crackers to boiling sugar/milk mixture. Or, reduce butter or margarine to ¼ cup and add ¼ cup peanut butter.