Ingredients
1/2
cup powdered sugar
2
tablespoons cornstarch
7 1/2
teaspoons unflavored gelatin
1/2
cup cold water
1 1/2
cups granulated sugar
1
cup light corn syrup
1/4
teaspoon salt
1/2
cup water
1
teaspoon vanilla
Preparation
Spray 9-inch square pan with cooking spray; line bottom and sides of pan with cooking parchment paper, leaving paper overhanging at 2 opposite sides of pan. In small bowl, mix powdered sugar and cornstarch. Sprinkle 3 tablespoons of the mixture over parchment paper in pan. In bowl of stand mixer, sprinkle gelatin over 1/2 cup cold water to soften; set aside.
In 2-quart saucepan, heat granulated sugar, corn syrup, salt and 1/2 cup water over medium heat, stirring constantly, until sugar is dissolved. Heat to boiling; cook, without stirring, about 15 minutes to 240°F on candy thermometer or until small amount of mixture dropped into cup of very cold water forms a ball that holds its shape but is pliable; remove from heat.
Slowly pour syrup into softened gelatin while beating on low speed. Increase speed to high; beat 6 to 8 minutes or until mixture is white and has almost tripled in volume. Add vanilla; beat on high speed 1 minute. Pour into pan; spread and smooth top with rubber spatula. Dust top of marshmallows with 3 tablespoons powdered sugar mixture. Let stand uncovered at least 8 hours or overnight.
Loosen sides of marshmallow mixture from pan and gently lift in one piece onto cutting board. Spray 2- to 3-inch star-shaped cutter with cooking spray. Cut marshmallows into stars. Sprinkle sides of each marshmallow with remaining powdered sugar mixture. Store tightly covered at room temperature up to 3 weeks.