- Place the gelatin into the bowl of a stand mixer along with 1/2 cup of the water. Have the whisk attachment standing by.
- In a small saucepan combine the remaining 1/2 cup water, granulated sugar, corn syrup and salt. Place over medium high heat, cover and allow to cook for 3 to 4 minutes. Uncover, clip a candy thermometer onto the side of the pan and continue to cook until the mixture reaches 240 degrees F, approximately 7 to 8 minutes. Once the mixture reaches this temperature, immediately remove from the heat.
- Turn the mixer on low speed and, while running, slowly pour the sugar syrup down the side of the bowl into the gelatin mixture. Once you have added all of the syrup, increase the speed to high. Continue to whip until the mixture becomes very thick and is lukewarm, approximately 12 to 15 minutes. Add the vanilla during the last minute of whipping. While the mixture is whipping prepare the pans as follows.
Turn the marshmallows out onto a cutting board and cut into 1-inch squares using a pizza wheel dusted with the confectioners' sugar mixture. (Kimberly's Note: I made more confectioners' sugar mixture. I put it into a ziploc bag and put cut marshmellows into the bag and shook so the marshmallows wouldn't stick to one another.). Once cut, lightly dust all sides of each marshmallow with the remaining mixture, using additional if necessary. Store in an airtight container for up to 3 weeks.