To make 36 medium or 16 large marshmallows.
Ingredients
2/3 cup water, divided
3 (1/4 oz) envelopes unflavoured gelatin
1 cup granulated sugar
1 cup light corn syrup
Pinch of kosher salt
1 tsp vanilla extract
1 cup confectioners' sugar, for dusting
Directions
Lightly oil the inside of an 8" by 8" pan with vegetable oil. Generously coat with confectioners' sugar and set aside.
Pour 1/3 cup of the water into the bowl of a stand mixer. Sprinkle the gelatin over the water, and let stand for about ten minutes, or until the gelatin has softened.
In a saucepan, off heat, combine the remaining 1/3 cup water and the granulated sugar, corn syrup and salt. Place the pan over medium-high heat. Clip a candy thermometer to the inside of the pan and make sure it does not touch the bottom. Cook the mixture without stirring until it reaches 240 degrees F. Brush down the sides of the pan with a pastry brush dipped in water, to gently wipe away any residual sugar crystals. With the mixer on low speed, very carefully add the hot syrup to the softened gelatin. Add the vanilla, increase the speed to medium-high and beat for eight to thirteen minutes until the mixture becomes very white, stiff and sticky.
Spread the mixture into the prepared pan using a lightly oiled spatula. With wet hands, press the batter evenly into the corners of the pan. Set aside for at least one hour, or until the mixture is firm and cool.
Sift the confectioners' sugar into a shallow dish or bowl. Run a wet knife around the edge of the cooled pan to loosen the marshmallow sheet. Remove the marshmallows from the pan. Cut into 16 or 36 squares, wetting the knife often to keep it from sticking. Toss each marshmallow in the confectioners' sugar until completely coated.
Storing your marshmallows: in a single layer or in layers separated by waxed paper. They will keep for at least one month when stored airtight at moderate temperature.
Variations: substitute sifted unsweetened cocoa or toasted shredded coconut for the confectioners' sugar used to coat the marshmallows, or fold one cup finely chopped cacao nibs, toasted almonds, mini chocolate chips, dried cranberries or any combination thereof into the stiff marshmallow mixture before spreading.


