• 1 cup water, divided
• 3 teaspoons gelatin
• 2 egg whites
• 2 cups granulated Imperial Sugar
• ¼ cup corn syrup
• Pinch of salt
• 1 teaspoon pure vanilla extract

Dusting powder:

• 1 cup powdered Imperial Sugar
• ½ cup cornstarch, sifted

1. Grease an 8 x 8-inch pan, then line with parchment paper. Grease utensils to prevent sticking.
2. Stir gelatin into ½ cup water and set aside.
3. Whisk 2 egg whites in a metal bowl until stiff peaks form. Hold in refrigerator for up to 30 minutes.
4. Combine sugar, corn syrup, and remaining water in a pot. Stir until mixed.
5. Over medium-high heat, bring the sugar mixture to a boil. Gently swirl the pan to evenly distribute heat. Cover saucepan and lower heat to medium.
6. Let syrup cook for 2 minutes; do not lift lid. After 2 minutes, remove lid and make sure there are no sugar crystals on the side of the pan. If there are crystals, cover saucepan for another minute to allow the condensation to wash down the sugar crystals into the syrup.
7. Clip a sugar thermometer to the side of the saucepan and cook until it reaches a temperature between 242°F–245°F. If you don’t have a sugar thermometer, check every 5 minutes until it reaches the firm-ball stage.
8. Remove from heat and let the bubbles subside. Pour the sugar syrup into a mixing bowl and stir in the gelatin. Mix on medium-low speed along the wall of the bowl to prevent the gelatin from being scorched by the hot sugar syrup.  Add the salt and increase the speed to medium-high.
9. Whisk on medium-high for up to 5 minutes until the marshmallow base is doubling in size and is white, fluffy and smooth. Mix for 3–5 minutes more minutes on high speed, allowing the marshmallow to volumize more (up to 3 times). Do not mix if the marshmallow base is already cooled down, as this will create tough marshmallows. While the marshmallow base is whisking, add the vanilla and egg whites to the marshmallow base and whisk for another minute on high speed to combine.
10. Scrape the marshmallow base into the prepared pan using a greased cake spatula. Spread the marshmallow evenly in the pan.
11. Combine the powder sugar and cornstarch and sift over the top of the marshmallow to set for at least 6 hours; cover lightly with plastic wrap during the curing process.
12. Flip the set marshmallow onto a work surface coated with cornstarch. Cut the marshmallows with a greased knife into desired shapes and size.
13. Toss the marshmallow in the cornstarch and store in an air-tight container or plastic food bag.