2 tablespoons (14 g) unflavored powdered gelatin (if using packets, you’ll need 2)
1 cup (8 fluid ounces) cool water
2 cups (400 g) granulated sugar
1/8 teaspoon cream of tartar
1 teaspoon pure vanilla extract
1/8 teaspoon kosher salt
5 tablespoons (70 g) unsalted butter, melted and cooled
8 to 9 cups (240 to 270 g) crisp rice cereal (recommended gluten free brands: Erewhon, Nature’s Path Organic)
Line an 8- or 9-inch square (or 9-inch x 12-inch, for smaller treats) baking dish with heavy-duty aluminum foil, and grease the foil with cooking oil spray, and set it aside.
In a small bowl, place 1/2 cup (4 fluid ounces) of the water, add the gelatin, and mix to combine well. Set the bowl aside and allow the gelatin to swell as it stands. Once the gelatin has swelled, transfer it to the bowl of a stand mixer (or a large bowl to use with a hand mixer).
In a medium, heavy-bottom saucepan, place the remaining 1/2 cup water, sugar and cream of tartar, and whisk to combine well. Cook the sugar mixture over medium-high heat until it reaches the softball stage, between 238°F and 240°F, on an instant read thermometer. Remove the saucepan from the heat immediately, and pour the cooked sugar mixture down the side of the bowl of the stand mixer into the gelatin mixture. Whisk to combine and allow the mixture to cool briefly. It will bubble. Add the vanilla and salt, and beat the mixture on medium-high speed with the whisk attachment (or with a hand mixer) until the mixture is white, thick and glossy. It should nearly triple in size. It is ready when the mixture pours off the whisk (or beaters) very slowly when the attachment is raised. You made marshmallows!
Add the melted butter to the marshmallows, and beat again on medium speed until combined. The marshmallows will decrease in size a bit. Add 8 cups of the crisp rice cereal. Spray a silicone spatula with cooking oil spray, and use it to stir together gently the marshmallow mixture and the rice cereal. Add up to 1 cup more crisp rice cereal, depending upon how gooey you would like your treats to be.
Scrape the mixture into the prepared pan, and smooth the top with the oiled spatula. Place in the refrigerator until set (about 15 minutes), and slice to serve. Store in an airtight container either in the refrigerator or at room temperature.
Originally published on the blog in 2013. Recipe tweaked slightly but mostly unchanged, photos mostly new, video new, text mostly new.