In a medium saucepan, bring the remaining water, sugar, corn syrup and salt to boil over medium high heat. When mixture reaches 240 degrees, remove from heat and slowly pour hot mixture over softened gelatin. Stir to dissolve gelatin.

Place bowl on stand mixer and whip on high speed until white and thick, about 4 minutes. In a separate Kitchen Aid bowl, whip the whites, vanilla and cinnamon on high speed to stiff peaks. Add the whites to the sugar mixture and beat until combined, about 30 seconds.

Grease a rubber spatula with pan spray and transfer the marshmallow to the prepared square pan. Use a greased mini offset spatula to spread the marshmallow and even out the top. Coat the top with some sifted powdered sugar. Place the uncovered marshmallow in refrigerator overnight.

The next day, run a small thin paring knife around the edges and flip out onto a cutting board. Cut into desired shapes and toss them in some sifted powdered sugar. Place in an airtight container for up to two weeks.