Nicole's Vegetarian Marshmallows

Prepare the Pan (5 minutes): Lightly grease a 9-inch square baking dish with cooking spray. Dust generously with 1/2 cup of confectioners' sugar, ensuring an even coating.

Bloom the Agar Agar (10-15 minutes): In a small saucepan, bring 1/2 cup of water to a boil. Remove from heat and whisk in the agar agar powder until fully incorporated. Allow the mixture to sit and dissolve completely, about 10 to 15 minutes.

Whip the Egg Whites (5-7 minutes): Using a stand mixer fitted with the whisk attachment, beat the egg whites until soft peaks form. Set aside.

Cook the Sugar Syrup (15-20 minutes): In another small saucepan, combine the remaining 3/4 cup water, granulated sugar, and corn syrup. Cook over medium-high heat, stirring occasionally, until the mixture reaches 250 to 265°F (121 to 129°C) on a candy thermometer, or when a small drop of syrup forms a firm ball in cold water. Remove from heat and immediately stir in the dissolved agar agar mixture.

Combine and Beat (8-10 minutes): With the stand mixer running, slowly pour the hot syrup into the beaten egg whites in a thin, steady stream, taking care to avoid splashing. Continue beating until the mixture is very stiff and glossy. Stir in the vanilla extract.

Set the Marshmallows (8 hours - overnight): Pour and spread the marshmallow mixture evenly into the prepared baking dish. Dust the top generously with the remaining 1/2 cup of confectioners' sugar. Let it stand at room temperature until fully set, ideally for at least 8 hours or overnight.

Slice and Serve (5 minutes): Once set, dip a sharp knife in very hot water and wipe dry. Slice the marshmallow mixture into 2-inch squares. Re-dip the knife in hot water between slices for clean cuts. Enjoy!