Lightly butter and dust a 9" square baking pan with powdered sugar.
In a small bowl, mix the gelatin and ½ cup cold water together. Set aside for 10 minutes to thicken up.
Place the remaining ½ cup of water and sugar in a deep saucepan over medium heat. Stir until sugar is dissolved.
Once the sugar is dissolved, add the gelatin. Do not stir! Allow the mixture to come to 240F.
Carefully pour the mixture in the bowl of a stand mixer fitted with the whisk attachment.
Beat on LOW speed for 2 minutes, then increase speed to HIGH for 8-10 minutes, until doubled in volume and super fluffy.
Pour into the prepared pan and smooth out with a spatula.
Dust with more powdered sugar then set aside uncovered for 2-3 hours, until set.
Slice into individual marshmallows to enjoy!
