01 -
Line a 23 × 23 cm baking pan with parchment paper and lightly grease with nonstick spray or oil.
02 -
Add 120 ml cold water and gelatin to the bowl of a stand mixer. Allow to sit undisturbed for 5–10 minutes to bloom.
03 -
In a medium saucepan, combine granulated sugar, corn syrup, salt, and remaining 60 ml cold water. Heat over medium, stirring until the sugar dissolves. Increase to medium-high and boil until mixture reaches 115°C, using a candy thermometer.
04 -
With the stand mixer on low, slowly pour the hot syrup into the bloomed gelatin. Gradually increase to high speed and whip for 10–12 minutes, until thick, glossy, and cooled slightly. Add cotton candy flavoring and desired food coloring; blend until uniform.
05 -
Spread marshmallow mixture evenly into prepared pan using a lightly oiled spatula. Smooth the surface. Let stand uncovered at room temperature for at least 6 hours or overnight until fully set.
06 -
In a small bowl, combine powdered sugar and cornstarch thoroughly.
07 -
Dust a work surface with a portion of the sugar-cornstarch mix. Turn out the set marshmallow slab, peel off parchment, and dust the top. Using a greased knife or cookie cutter, slice into squares or shapes. Roll each piece in remaining dusting mixture for an even coat.
08 -
Place marshmallows in an airtight container at room temperature for up to 1 week.