In the mixing bowl of a stand mixer with a whisk attachment, mix the gelatin with 1/2 cup of the cold water for a few seconds, then let it sit for 5 minutes so the gelatin can bloom.
1 cup water, 1 teaspoon unflavored powdered gelatin
In a saucepan, bring the sugar, corn syrup, salt and remaining 1/2 cup cold water to a boil over medium-high heat.
1 1/2 cups granulated sugar, 1 cup light corn syrup, 1/8 teaspoon kosher salt
Continue cooking until the temperature reaches 240°F on a candy thermometer, then remove from heat and pour over the gelatin mixture.
Add the vanilla extract and beat on low speed for 2 minutes. Increase the speed to high and beat for about 10 to 12 minutes until the mixture turns thick, white and glossy.
1 teaspoon vanilla extract
Store in an airtight container in the refrigerator for up to one month.