Ingredients
¼ cup/35 g cornstarch
¼ cup/30 g confectioner’s sugar
1 cup/240 ml water
¾ oz/20g granulated gelatin
10 ½ oz/300 g superfine sugar
1/8 tsp cream of tartar
2 large egg whites, warmed to room temperature
½ to 1 tsp peppermint extract (depending on how strong you like it to be)
Red food coloring (I used 1 tsp of beet powder mixed in 2 Tbsp water)
Neutral oil for greasing
Instructions
- Sift the cornstarch and confectioner’s sugar with a fine mesh sieve over a small mixing bowl. Sift 2 Tbsp over a square 9 in/23 cm baking pan. Grease the sides lightly with a little a neutral-tasting oil. Keep aside.
- Place ½ cup/120 ml of water in a small heat-proof mixing bowl or measuring cup. Sprinkle the gelatin on top and allow to sit undisturbed.
- Pour the remaining water into a medium saucepan, add the sugar and cream of tartar. Cover with a lid and heat on medium-low heat until all the sugar is dissolved and the temperature reaches 240F/115C on an instant-read or candy thermometer.
- While the sugar cooks, prepare the egg whites. Place the egg whites in the bowl of a stand mixer and using the whisk attachment, whisk on medium-high speed until the egg whites turn foamy and eventually produce stiff peaks, about 5 minutes. Stop the mixer.
- Once the sugar syrup reaches 245F/115C, pour it in a thin stream into the gelatin at the side of the mixing bowl. It will start to foam, so add it slowly to prevent it from spilling. Stir with a fork to dissolve the gelatin in the syrup, it will take a few minutes to get it smooth. Then pour the hot sugar-gelatin syrup into the egg whites in a thin and steady stream while continuing to whisk the egg whites on medium-high speed. Once the syrup is added, continue to whisk for 1 additional minute and then increase the speed to high and whisk until you get stiff peaks (the foam should be white in shiny white in color and will hold its shape). Whisk the peppermint oil for 1 minute on high speed. Then stop the mixer and add a few drops of the coloring and whisk for 3 to 4 seconds just long enough to create a few swirls (avoid the urge to over-mix or it will become uniformly pink). Remove the bowl from the mixer and using a silicone spatula transfer the mixture to the prepared baking pan. Take a small offset spatula and lightly grease it with a little oil and even the top layer. Allow the pan to rest covered for at least 4 hours preferably 6 hours. The marshmallow will be ready once it is cool and spongy to touch in the center.
- To cut, dust a clean surface with a little bit of the cornstarch-sugar mixture. Run a small knife around the edges of the pan to release the marshmallow. You might need to gently pull it from the sides to help release it. Cut into 1 in/2.5 cm squares with a sharp knife (you can grease the knife with a little oil to prevent sticking). Dust the squares with a little cornstarch-sugar mixture and store in an airtight container for up to 1 week.
