Once in your lifetime, you should make these.
2 cups sugar
3 envelopes unflavored gelatin
1/4 teaspoon salt
1/3 cup Confectioners' sugar
3 tablespoons cornstarch
1 cup cold water
1 teaspoon clear vanilla extract
In a medium saucepan, combine sugar, gelatin and salt. Stir in water and let sit 5 minutes for gelatin to soften. Meanwhile, in a small bowl, mix together Confectioners' sugar and cornstarch. Butter the bottom and sides of an 8" x 8" pan. Divide the cornstarch mixture into thirds and use one third to coat the pan.
Return to gelatin mixture and cook over low heat just until the sugar dissolves, about five minutes. Allow to cool and stir in vanilla extract. Transfer mixture to a large bowl and beat with electric mixer until soft peaks form (this will take about ten minutes). Pour into prepared pan and top with another third of the cornstarch mixture. Let stand overnight at room temperature to set.
Dip a small, sharp knife into warm water and cut marshmallows into squares, dipping each once in the remaining cornstarch mixture. Store, covered at room temperature for up to several weeks. Makes about 25 large ones. Notes: They're great dipped in dark chocolate, in hot chocolate of course, and even in your coffee.