Homemade marshmallows have a creamier texture that pairs perfectly with hot chocolate!
Very lightly spray or grease a 13"x9" baking dish and sprinkle with icing sugar.
In the bowl of a stand mixer fitted with a whisk attachment, combine 1/2 cup cold water and gelatin. Let stand for 10 minutes or until soft.
Meanwhile, in a small heavy saucepan, combine sugar, corn syrup, salt, and remaining 1/2 cup of water and bring to boil over medium heat, stirring just until sugar dissolves.
With a pastry brush dipped in water, brush inside the pan to remove any sugar crystals. Increase heat to high and cook, without stirring, until mixture registers 244° on a candy thermometer.
With mixer at low speed, immediately pour sugar mixture into gelatin mixture and beat at low speed for a minute or two until combined, then at medium speed until fluffy. Increase speed to high and beat until mixture is thick, white, and very fluffy.
Beat in extract. Use a wet spatula to scrape out the mixture into the prepared pan.
With wet hands, press the marshmallow mixture to an even thickness in pan and generously sprinkle with icing sugar to fully cover.
Let stand, uncovered, for at least 8 hours or overnight. Turn out onto a cutting board and use kitchen shears or large scissors to cut marshmallows into 1 1⁄2" squares. Dip cut edges in icing sugar to keep from sticking.