Sprinkle gelatin over 1 cup of cold water in a stand mixer bowl. Let sit for 10 minutes.
In a saucepan, combine 1 cup of water, cane sugar, and sea salt. Stir over medium heat until sugar dissolves.
Increase heat to medium-high and boil until the syrup reaches 240°F on a candy thermometer.
Slowly pour the hot syrup into the bloomed gelatin while mixing on low speed.
Increase speed to high and whip for 10-12 minutes until thick and fluffy.
Add vanilla extract and mix for another 30 seconds.
In a small bowl, mix powdered sugar, cinnamon, and cane sugar.
Grease a 9x13-inch pan and dust lightly with some cinnamon sugar.
Pour the marshmallow mixture into the pan, smooth the top, and sprinkle more cinnamon sugar on top.
Let set at room temperature for 6-8 hours.
Once set, cut into squares with a greased knife or kitchen scissors.
Toss each marshmallow in the remaining cinnamon sugar mixture.
Store in an airtight container at room temperature for up to a week.