These homemade mocha marshmallows are a little time-consuming to make, but the ends totally justify the means - they're fluffier and softer than store-bought, and can be customized with whatever flavour happens to catch your fancy (like, say, a coffee-house inspired blend of cocoa, coffee and cinnamon.)
Sift together the icing sugar and cocoa powder into a small bowl.
Lightly spray a 9-inch square pan with nonstick cooking spray and dust with 2 tbsp of the dusting mixture.
Make the Marshmallows:
In a small bowl, combine the gelatin and ½ cup of cold water, and set aside to bloom. In a second small bowl, combine cocoa, espresso powder, cinnamon and boiling water, and whisk until smooth.
In a small saucepan set over medium-high heat, combine sugar, corn syrup, and the remaining ½ cup of cold water. Cook, stirring constantly, until the sugar dissolves, and then continue cooking without stirring until the mixture reaches 240F.
Meanwhile, in the bowl of a stand mixer fitted with the whisk attachment, whip egg whites, coffee liqueur and salt at a high speed until stiff peaks form. Scrape into a clean bowl, then quickly wash and dry the mixer bowl and put it back on the stand mixer.
Add the gelatin and cocoa mixtures to the stand mixer bowl, then quickly pour in the hot syrup. Beat at high speed for about 4 minutes, or until thick and tripled in volume. Gently fold in the egg whites, then spread evenly into the prepared pan. Dust with 2 tbsp of the remaining dusting mixture.
Chill the marshmallows for at least 2 hours, or until set. Using a sharp knife dipped in icing sugar, cut the marshmallows into 2 inch squares. Toss with the remaining coating mixture to coat on all sides, then transfer to an airtight storage container until ready to eat.
Recipe by Crumb: A Food Blog at https://www.crumbblog.com/homemade-mocha-marshmallows/