01 -
Line a 23×23 cm baking pan with parchment paper and lightly grease with cooking spray or a thin layer of oil.
02 -
In the bowl of a stand mixer, combine 120 ml of cold water and the gelatin. Let sit for 5–10 minutes until fully bloomed.
03 -
In a medium saucepan, combine the granulated sugar, corn syrup, salt, and remaining 60 ml of water. Heat over medium heat, stirring until sugar dissolves. Increase to medium-high and bring to a boil. Cook until mixture reaches 115°C on a candy thermometer.
04 -
With mixer on low speed, carefully pour the hot sugar syrup into the bloomed gelatin. Gradually increase speed to high and beat for 10–12 minutes, until mixture becomes thick, fluffy, and slightly cooled. Add the cotton candy flavoring and a few drops of food coloring, mixing until evenly combined.
05 -
Pour the marshmallow mixture into the prepared pan and smooth the top with a greased spatula. Allow to set at room temperature for 6–8 hours or overnight.
06 -
Mix the powdered sugar and cornstarch in a small bowl. Dust a work surface with this mixture. Turn the marshmallow slab onto the surface, remove parchment paper, and dust the top with the powdered sugar mixture. Use a greased knife or cookie cutters to cut into squares or shapes. Toss cut marshmallows in the powdered sugar mixture until fully coated.