Coat an 8 by 8 baking pan or dish lightly with cooking spray and set aside.

For the Bloom

1. Whisk together the water and gelatin in a small microwave-safe bowl and set aside. It needs to set for at least five minutes to allow the gelatin to soften.

For the Syrup

1. Add 1/4 cup of the corn syrup to the bowl of a stand mixer and set aside while cooking the simple syrup.
2. Meantime, add the remaining 1/4 cup of corn syrup, the sugar, water, and salt to a medium saucepan. Bring to a boil over high heat, stirring occasionally. Cook until mixture reaches 240 degrees on a candy thermometer (soft ball stage) and remove from heat.
3. Meantime, place the bowl of gelatin and water in a microwave and heat for 30 seconds to soften the mixture. Add the mixture to the corn syrup in the stand mixer bowl. Turn the mixer on low and allow it to continue running on low while you’re waiting for the syrup mixture to reaches 240 degrees.

For the Mallowing

1. With the mixer running on low speed, slowing pour the hot syrup into the mixing bowl. Turn mixer to medium speed and mix for 5 minutes. Turn mixer to medium high speed and mix for an additional 5 minutes. Add the vanilla extract and mix on highest speed for 2 minutes.
2. Spread the mallow mixture into the prepared pan, using an offset spatula to spread it into the corners. Liberally dust the top of the mallow mixture with the classic coating. Allow the mallow mixture to rest in a cool dry place for at least 6 hours.
3. Run a sharp knife around the edges of the pan. Invert the marshmallow slab onto a counter or piece of parchment paper. Sift some of the classic coating over the top. Using a pizza cutter or sharp knife, cut into desired shapes. Dip any sticky edges in more of the classic coating. Shake off any excess coating.
4. Store marshmallows in an airtight container for up to one week.

For the Classic Coating

1. Whisk the powdered sugar and cornstarch together in a medium bowl. Store in an airtight container. Use as needed for dusting marshmallows.

Recipe adapted from the book Marshmallow Madness by Shauna Sever