Serves: Makes 40 (1¼-inch) marshmallows
- 2½ cups sweetened shredded coconut
- ¾ cup cold water
- 1¼ cups granulated sugar
- 2 tablespoons light corn syrup
- 2 (¼-ounce) packets unflavored gelatin
- 3 large egg whites, at room temperature
- 1 tablespoon pure vanilla extract
- Position a rack in the center of the oven. Preheat the oven to 300°F.
- Spread the coconut in an even layer on a large rimmed baking sheet. Toast the coconut, stirring every 3 minutes, until it is rich golden brown, about 12 minutes. (Stirring frequently will ensure even browning and also prevent the coconut from burning at the edges of the pan.) Remove from the oven and set aside.
- Meanwhile, cut a rectangle of parchment paper to fit the bottom of a 12 by 8 by 1-inch jellyroll pan. Spread ¾ cup of the toasted coconut in an even layer on the parchment. Set the pan aside and reserve the rest of the coconut.
- Combine 1/ ³ cup of the water, the sugar, and corn syrup in a medium saucepan. Bring to a boil over medium heat, stirring to dissolve the sugar. Once the sugar has dissolved, cook the syrup without stirring until the mixture reaches 265°F on a candy thermometer, 8 to 10 minutes.
- While the syrup is cooking, prepare the gelatin. In a small, microwave-safe bowl, sprinkle the gelatin over the remaining water, tilting the bowl a bit to wet all of the gelatin granules. Let it sit until spongy, about 5 minutes. Warm the gelatin in a microwave to liquefy it, about 20 seconds. Set aside.
- Put the egg whites in the bowl of a stand mixer fitted with the whisk attachment or in a large bowl with a hand mixer. When the sugar syrup is just below 265°F, begin beating the egg whites on medium-high speed until glossy with soft peaks. Turn the mixer off momentarily.
- Once the sugar syrup reaches 265°F, remove the pan from the heat, turn the mixer to medium speed, and pour the sugar syrup in a slow, steady stream down along the sides of the bowl. Beat until all the syrup is incorporated, and then slowly pour the gelatin mixture into the egg whites. Beat for 3 minutes. Add the vanilla and beat, scraping down the sides of the bowl once with a rubber spatula, until incorporated, 30 seconds longer.
- Using a rubber spatula, lift globs of the marshmallow mixture and gently plop them on the coconut, without disturbing the coconut. Cover the coconut with these mounds, and then use a rubber spatula to gently spread them into an even layer. The marshmallow mixture should be even with the top of the jellyroll pan. Evenly and generously sprinkle ¾ cup of the reserved coconut over the top of the marshmallows. Set the pan aside in a cool, dry spot to set, about 3 hours or up to 12 hours.
- Use a ruler and long, thin-bladed sharp knife to measure and cut the marshmallows into 1¼-inch squares. Rinse and dry the knife as needed to keep it clean. Put the remaining toasted coconut in a medium bowl. Gently lift the marshmallow squares from the parchment and toss them in the coconut to coat all sides, gently pressing coconut onto any bare spots. Transfer them to a clean baking sheet. Repeat until all the marshmallows are coated.
Storing: Store the marshmallows on a baking sheet covered with aluminum foil until ready to package. The marshmallows will keep at room temperature for 1 week.