Combine powdered sugar and corn starch in a small bowl. Sift half of the mixture over 3 sheet trays to coat. Reserve the other half of the mixture for later.
Pour 1/2 cup cold water into a stand mixer fitted with a whisk attachment. Sprinkle in the gelatin powder and let it dissolve and soften, about 15 minutes.
In a heavy bottomed saucepan fitted with a candy thermometer, combine 1/2 cup water, sugar, corn syrup and sea salt. Over medium heat bring the mixture to a boil and cook until it reaches 240F or the soft-ball stage. Immediately remove from heat.
Turn the stand mixer on low and break up gelatin. With the mixer running slowly pour hot sugar mixture over the bloomed gelatin. Slowly turn the mixer up to medium speed and continue to beat the mixture for 15-20 minutes; it will become light, fluffy, white in color and triple in volume. Add vanilla and food coloring and beat 1 minute.
Prepare a large pastry bag fitted with a star tip. Spray the inside of the pastry bag with cooking spray. Transfer the marshmallow mix to the pastry bag and pipe stars onto the prepared sheet trays, making sure to leave space between each marshmallow. Sprinkle the finished marshmallows with the remaining sugar and cornstarch mixture. Let sit at room temperature for a couple hours or overnight.
Recipe Courtesy of Megan Mitchell
As Seen on Secrets of a Food Stylist