Ingredients
3 envelopes unflavored gelatin
1 cup cold water, divided
2 cups granulated sugar (cane sugar worked just fine)
1/2 cup light corn syrup
1/4 teaspoon salt
2 large egg whites
1/2 tablespoon vanilla
Mixture 1/2 C powdered sugar + 1/2 C cornstarch
Preparation
Oil bottom and sides of a 13- by 9- by 2-inch rectangular metal pan and dust all sides with mixture sugar+cornstarch
In bowl of an electric mixer sprinkle gelatin over 1/2 cup cold cold water, and let stand to soften.
In a 3-quart saucepan cook granulated sugar, corn syrup, second 1/2 cup of cold water, and salt over low heat, stirring with a wooden spoon, until sugar is dissolved. Increase heat to moderate and boil mixture, without stirring, until a candy thermometer registers 240°F. Turn the mixer on low speed and, while running, slowly pour the sugar syrup down the side of the bowl into the gelatin mixture. Once you have added all of the syrup, increase the speed to high. Continue to whip until the mixture becomes very thick and nearly triple in volume approximately 12 to 15 minutes. In medium bowl beat egg whites until they just hold stiff peaks, add vanilla or any other flavor and/or color. Add whites and vanilla into sugar mixture until just combined. When ready, pour the mixture into the prepared pan, using a lightly oiled spatula for spreading evenly into the pan. Dust the top with enough of the remaining sugar and cornstarch mixture to lightly cover. Reserve the rest for later. Allow the marshmallows to sit uncovered for at least 4 hours and up to overnight.
Turn the marshmallows out onto a cutting board and cut into 1-inch squares using a pizza wheel dusted with the confectioners’ sugar mixture. Once cut, lightly dust all sides of each marshmallow with the remaining mixture, using additional if necessary. Store in an airtight container for up to 3 weeks.
