HOT COCOA-POWDERED SUGAR MIXTURE: Place a sifter over a medium sized bowl. Add the powdered sugar, hot cocoa mix, cocoa powder and cornstarch and sift together. Set aside.

MARSHMALLOWS: Brush a 9-inch x 13-inch glass baking pan with oil. Sprinkle some of the hot cocoa-powdered sugar mixture evenly over the oil (this will prevent the marshmallows from sticking to the bottom of the pan and make it easier to cut them).

In the bowl of a stand mixer, affixed with the whisk attachment, add 1/2 cup cool water and three envelopes of gelatin. Mix until ingredients are combined.

In a medium sized pot, on the stove top over medium heat, add the sugar, corn syrup, salt and 1/2 cup water. Stir ingredients until the sugar has dissolved. Change the heat to high and cook the mixture, WITHOUT STIRRING, until the mixture reaches 240-degrees (Fahrenheit) on a candy thermometer.

Remove the pot from the stove and set the stand mixer to low speed and slowly pour the sugar mixture into the softened gelatin. Increase the speed to high and whip the mixture. 5-minutes into mixing, stop the mixer and add the hot cocoa mix, chocolate extract and vanilla extract. Continue mixing on high until the mixture is lukewarm and thick and fluffy. Process may take 3-10 minutes of whipping.

Pour marshmallow mixture into prepared pan, in an even layer. Sprinkle some of the hot cocoa mix-powdered sugar mix over the top of the marshmallows. Save leftover sugar mixture to roll the cut marshmallows into. Let marshmallows set for several hours, or overnight, before cutting.

To cut marshmallows, grease a sharp knife, and cut into desired sized squares. Roll cut marshmallows in the hot cocoa mix-powdered sugar.