In the bowl of a stand mixer fitted with the whisk attachment, empty the contents of the strawberry jell-o pack and add the 80 ml water. Stir to combine and set it aside.
Take a 9x9 inch baking pan grease it with a flavourless oil generously everywhere. Coat the insides of the pan with equal parts icing sugar and cornflour. I sift the mixture onto the pan and shake it to coat evenly. THIS IS AN IMPORTANT STEP to avoid the marshmallows from sticking to the pan.
In a heavy bottomed saucepan add the sugar, light corn syrup and water. On medium-low heat, bring this mixture up to 240F (use a candy thermometer).
When the mixture reaches 240F take it off the heat. Start the stand mixer on low speed and very slowly drizzle this hot sugar syrup along the side of the bowl as the mixer keeps running. BE EXTREMELY CAREFUL.
Once all the syrup is poured, crank up the speed to high and let it whip for 8 minutes or until the bowl is cool to touch. The mixture will become extremely light and fluffy.
At this stage, work quickly and transfer this marshmallow fluff to the prepared pan and spread it evenly as best as you can. The mixture will start setting very quickly and it will be extremely sticky. Sift some of the icing sugar and cornstarch mixture on the top surface and let it sit outside on the counter to dry overnight.
Cut into squares:
One a clean and dry surface, sift the icing sugar and cornstarch mixture evenly and invert the dried marshmallow from the baking pan.
Take a very sharp knife, grease it slightly with a flavourless oil and make straight sharp cuts to cut your marshmallow to your desired size.
Sprinkle more of the icing sugar and cornflour mix and toss them to coat all sides.