Bloom the Gelatin: In a bowl, combine 1/2 cup of cold water with the gelatin and let it sit for about 5 minutes.
Prepare the Sugar Syrup: In a saucepan, mix the remaining water, granulated sugar, corn syrup, and salt. Heat over medium heat until the sugar dissolves, then increase the heat and bring to a boil until it reaches 240°F (115°C) on a candy thermometer.
Combine and Whip: Slowly pour the hot sugar mixture into the gelatin mixture while whisking continuously using a stand mixer or hand mixer.
Beat Until Fluffy: Beat the mixture on high speed for 8-10 minutes until it becomes thick and fluffy.
Add Flavor and Color: Stir in the cotton candy flavoring and gel food coloring until well combined.
Set the Marshmallow Mixture: Pour the mixture into a prepared pan lined with parchment paper and smooth the top with a greased spatula. Let it set at room temperature for at least 6 hours or overnight.
Prepare the Coating: In a small bowl, mix the powdered sugar and cornstarch.
Cut the Marshmallows: Dust a surface with the powdered sugar mixture, turn the marshmallow slab onto the surface, remove parchment paper, and dust the top with more powdered sugar mixture.
Shape the Marshmallows: Cut into squares or use cookie cutters for fun shapes, then toss them in the powdered sugar mixture to prevent sticking.
Enjoy and Store: Store the marshmallows in an airtight container at room temperature for up to 2 weeks.
