01 -
In the bowl of a stand mixer, whisk powdered gelatin with half of the cold water and allow to stand for 8–10 minutes to bloom.
02 -
Whisk together the remaining water, granulated sugar, corn syrup, and kosher salt in a medium saucepan over medium heat. Simmer for 6–8 minutes, whisking constantly, until the mixture becomes translucent. Remove from heat.
03 -
With the mixer on low and using a whisk attachment, slowly stream the hot sugar mixture into the bloomed gelatin. Once fully combined, continue whisking on low for 1 minute.
04 -
Increase stand mixer speed to high and whisk for 10 minutes until a thick, fluffy white mixture forms.
05 -
Reduce the mixer speed to low, add cotton candy flavouring, and mix for 1 minute. Divide mixture evenly into two bowls and tint one pink and the other blue with food colouring.
06 -
Dust a 23 x 33 centimetre baking pan with half of the powdered sugar. Alternately spoon coloured marshmallow mixtures into the pan. Level the top with a rubber spatula and dust the surface with remaining powdered sugar. Cover with plastic wrap and let set at room temperature for 8–12 hours.
07 -
Once firmly set, transfer the marshmallow slab to a cutting board. Dust away excess powdered sugar and cut into 2.5 centimetre squares. Serve and enjoy.