Instructions

1. Prepare the Pan: Brush the 9 x 9 inch square pan with Canola oil. Using a fine mesh strainer, dust the pan with confectioner's sugar and tap out the excess. Set aside.
2. Prepare the Gelatin: In a stand mixer (fitted with a whisk attachment), add ½ cup of water to the stand mixer bowl, sprinkle in the gelatin, over the water so that the gelatin has contact with the water - stir just a little bit. Allow the mixture to sit while you make the sugar syrup.
3. Prepare the Sugar Syrup: In a medium-large, heavy-bottomed saucepan (3-4 quarts) or pot, add granulated white sugar, corn syrup, kosher salt, and ½ cup of water. Place the candy thermometer on the side. Bring the mixture to a boil over medium heat. Make sure to stay and watch the mixture because it may boil up and you might need to turn the heat down. Boil until the mixture becomes 240 degrees F (soft-ball stage). Once it gets to that temperature, remove the pan from heat and turn off the stove top and allow to stand until the bubbles die down.
4. Add the Sugar Syrup to the Gelatin Mixture: Set the stand mixture with the gelatin mixture on low speed, carefully pour the sugar syrup, gradually, down the side into the gelatin mixture, slowly increase the speed up to high (about 5 minutes). The marshmallow mixture should form a thick ribbon when you lift up the whisk. Add the vanilla.
5. Allow the Marshmallow to Set: Add the marshmallow mixture (it's going to be super sticky) into the prepared 9 x 9 inch pan. Allow the marshmallow to stand at room temperature for 4 hours or overnight or until the top is no longer sticky and you should be able to pull the marshmallow away from the sides.
6. Cut the Marshmallows: When the marshmallow is set, dust a cutting board with confectioner's sugar, you can use a baking (rubber) spatula to separate the marshmallow from the sides of the pan, gently separate the marshmallow from all sides of the pan. Turn the pan over on the prepared surface. Dust all the surfaces of the marshmallow with confectioner's sugar. Wipe Canola oil on a chef's knife (to prevent sticking) and slice the marshmallow. When the marshmallow is sliced, dust all surfaces of the sliced marshmallows with confectioner's sugar (this will prevent them from sticking to each other).