⅔ cup powdered sugar
⅓ cup cornstarch
1 ½ cups cold water, divided
3 packets unflavored gelatin (about 2 ½ Tbs)
¼ tsp salt
⅔ cup light corn syrup
2 cups granulated sugar
2 tsp vanilla extract
scant ½ tsp peppermint extract
2-3 drops red food coloring
Line a 9×13” pan with nonstick foil (or spray regular foil lightly with cooking spray). Set aside
In a small bowl, whisk together the powdered sugar and cornstarch; set aside.
Pour ¾ cup of the cold water into the bowl of a stand mixer. Sprinkle the gelatin over the water. Let stand until the gelatin becomes very firm, about 15 minutes. Sprinkle with salt.
In a small saucepan, mix the remaining ¾ cup water and the corn syrup. Pour the sugar into the center of the saucepan. Bring to a boil over medium-high heat, gently swirling the pan, until the sugar has dissolved completely and the mixture reaches 240°F, about 10-15 minutes.
Carefully pour the hot syrup into the center of the mixer bowl with the softened gelatin, avoiding the sides of the bowl as much as possible. Using the whisk attachment, turn mixer onto low speed. Gradually increase the speed to high and whip until the mixture is very thick and stiff, about 7 – 10 minutes, scraping down the bowl as needed. Add the vanilla and peppermint extract and mix until well blended. Turn off mixer and place 2 –3 drops of red food coloring on top of the whipped mixture (space drops evenly throughout the bowl). Pulse 2 or 3 times until gently swirled. Do not overmix, or you will just have pink marshmallows.
Working quickly, scrape the mixture into the oiled pan using an oiled spatula. Smooth the top into an even layer. Sift 2 Tbs of the powdered sugar mixture over the pan. Cover and let sit overnight at room temperature.
The next day, turn the marshmallow slab out onto a cutting board and peel off the foil. Sift 2 tablespoons of the powdered sugar mixture over the slab of marshmallows. Using a sharp knife that has been rubbed with oil, cut into 1-inch square marshmallows. Or use cookie cutters to make fun shapes. (If you are using cookie cutters and don’t want them to be 1” tall, then spread soft marshmallow mixture into a foil lined half-sheet baking pan before letting them set overnight.)
Place the remaining powdered sugar mixture in a large Ziploc bag. Working with 3 or 4 marshmallows at a time, toss the marshmallows in the bag with the powdered sugar mixture, then toss in a fine-mesh strainer to remove any excess powder.
Marshmallows can be stored in an airtight container or bag for up to 2 weeks.
Makes about 90 square marshmallows
(Adapted from America’s Test Kitchen)