Place sugar in a plastic baggie - 1 bag, ¾ cup sugar for each colour you plan to use.
Add a drop or two of food colouring to each bag, press most of the air out of the bag, and seal with the zipper.
Gently massage the sugar around to distribute the food colouring evenly throughout the sugar, taking care to break down any clumps.
Once the colour is evenly distributed with no clumping, set bags aside.
Make the Marshmallow:
In a small, microwave safe bowl, sprinkle the gelatin over ¼ cup of water, set aside.
In medium saucepan, combine remaining cup of sugar, with remaining ¼ cup of water and salt.
Cook over medium heat, stirring constantly, until sugar is dissolved. Bring to a boil and continue to cook – without stirring – until mixture reaches 240°F on a candy thermometer.
Remove from heat and add gelatin mixture, stirring until dissolved and completely combined, with no lumps of gelatin.
Transfer sugar syrup to the bowl of a stand mixer, allow it to cool for 5 minutes.
Beat sugar syrup in a standing mixer (or with a hand held electric mixer) on medium speed until it becomes opaque/white.
Once syrup is no longer clear, add the vanilla and turn the mixer speed up to high.
Continue whipping the syrup until it is thick, white, glossy, and almost triple the original volume. This may take up to 10 minutes.
Pipe your Peeps:
Carefully spoon the marshmallow into a large pastry bag. Let it sit for a few minutes while you prepare your sugars:
Give each bag of coloured sugar a quick shake / massage to break up any clumps of dried sugar. Transfer half of each sugar to individual plates, for piping. Set aside.
Cut a small amount off the end of the pastry bag, so the opening is maybe ½″ across.
Pipe your peeps directly onto the sugar plates. I use pipe a short line downward, then a second little swoop up to create the body of the chick - see the post for photos of how to do this.
If your marshmallow is oozing rather than holding its shape, let the bag sit (open side facing up!) for 5 minutes or so, to set up a little.
Once your peeps are piped, shake the reserved sugar over each corresponding plate of peeps, completely coating each marshmallow entirely.
Allow to set for an hour or so, until firmed up.
Once the marshmallows are set, carefully shake off excess sugar, arrange peeps on a clean work surface.
Measure the cocoa powder into a small bowl. Add just enough water to form a thick “paint”, use a toothpick to apply eyes to each chick.
Transfer peeps to an airtight container for storage.
Video
Notes
The nutritional info isn't super accurate, as you will not use all of the coloured sugar.