Enjoy these creamy, light pillows of sweetness alone or toasted and sandwiched between two graham crackers with a slab of melting chocolate - aka S’mores. :) You'll need a 5-quart heavy-duty mixer to beat the marshmallow mixture. Leave the marshmallows uncovered overnight at room temperature before cutting. (Torture!)
Line a baking pan with parchment paper and lightly coat the paper and the sides with spray oil.
Put gelatin in a small bowl and add 3 tablespoons of water; stir. Set aside.
Combine 1 cup of sugar with corn syrup in a large, sauce pan.
Clip candy thermometer on pan, with tip in liquid. Cook and stir over medium heat until mixture reaches 240°F.
Meanwhile, pour the egg whites into the bowl of a stand mixer fitted with the whip attachment. Use the tip of a paring knife to scrape vanilla bean seeds into the bowl.
When the sugar syrup reaches 240°F, begin to beat the egg whites on medium speed. When whites form soft peaks, add remaining 1 cup of sugar; continue beating.
When the sugar syrup reaches 250°F, remove from heat and add softened gelatin. (The sugar syrup will foam up and triple in volume.)
Increase the mixer speed to high and slowly pour syrup into the beating egg whites, aiming for the side of the bowl. (Be cautious as this liquid is extremely hot.)
Once all syrup is added, reduce mixer speed to medium-high and beat until the marshmallow mixture is lukewarm, about 15 minutes.
Use a spatula to scrape the marshmallow mixture into the prepared pan and smooth it evenly to the sides. (This is a sticky business!)
Cool completely, uncovered at room temperature.
To cut the marshmallows, sift a thin layer of powdered sugar over onto a work surface.
Sift about 2 cups powdered sugar into a large bowl.
Lift parchment paper and marshmallow from the pan. (Should some of it stick to the sides, run a thin-bladed knife around the edges first.) Place marshmallow side down on to your work surface and remove parchment paper.
Sift about ½ cup powdered sugar evenly over the top.
Use a ruler as a guide and cut the marshmallows with a lightly oiled sharp knife. Cut marshmallow sheet into 1-inch squares (or your desired shape). Use a pressing motion with the knife instead of pulling it through.
After cutting, add marshmallows, several at a time to the bowl of powdered sugar. Toss to coat lightly.
Store marshmallows in an airtight container at room temperature for up to 1 month.