2 T. unflavored gelatin
1/2 c. cold water
2 c. granulated sugar
3/4 c. light corn syrup
3/4 c. hot water
2 t. vanilla
1/4 c. powdered sugar
1/4 c. cornstarch

Before you begin, line an 8x8 square pan with parchment paper.

1.  Combine gelatin and ½ cup cold water in large mixer bowl.  Let stand while you cook syrup.

2.  Combine sugar, corn syrup and hot water in 3 quart heavy saucepan.  Place over high heat and stir constantly with a wooden spoon until all sugar crystals are dissolved.  Wash down sides of pan with a pastry brush dipped in hot water, then clip on thermometer.  Cook without stirring to 245 degrees, about 10 minutes.  Wash down sides of pan twice more while mixture cooks.  Remove from heat.

3.  Set mixer at highest speed.  Slowly pour hot syrup mixture in a thin stream over gelatin in bowl.  Continue beating for about 15 minutes, or until ribbons drop off the beater and retain their shape on the surface of the mixture.  Add vanilla toward end of beating.  Use a rubber scraper to remove mixture from bowl into prepared pan.  Swirl from center to edges of pan to level.  Let firm overnight at room temperature.

4.  Mix cornstarch and powdered sugar, then sift into a cookie sheet with 1 inch sides.  Loosen sides of marshmallow with a small spatula dipped in cold water and turn out onto cookie sheet.  Lay a damp folded towel on paper for a few minutes, then peel off paper.  Heap cornstarch mixture on marshmallow, then cut in 1 inch strips with serated knife dipped in cold water.  Roll strips in cornstarch mixture, then cut each into 8 1 inch cubes with scissors dipped in cold water.  Tumble cubes in cornstarch mixture and let stand for about an hour to dry.  Brush away excess cornstarch mixture with a clean, dry pastry brush.