Preheat your oven to 200F (100C) if using, and line 1 large baking trays with parchment paper.
In a stand mixer with the whisk attachment, or a large bowl with a handheld mixer, whip the cool reduced aqufaba and cream of tartar until it reaches medium to stiff peaks.
Slowly add the sugar one spoonful at a time to the meringue while continuing to whisk until the meringue is thick and glossy and had reached stiff peaks.
Quickly but gently fold in the sifted cacao powder into the meringue without over mixing.
Transfer the meringue into a piping bag with your favorite pastry tip like the Wilton 1M.
Pipe onto the prepared baking tray, keeping 2 cm between each meringue cookies. To make small meringues, try to pipe them at 3 cm high to 2 cm diameteré
If using a dehydrator, cook at 160F ( 71C) for 4h. If using an oven, cook at 200F (100C) for 1h30 to 2h if using the oven, adjusting the cook time to how dry your meringues are when you test them.
Once cooked, turn off your oven and let the meringues continue to dry until they are room temperature or overnight.
Dip parts of each meringues into the chocolate and decorate. according to your preference. Leave to cool on a piece of parchment paper
Store in an airtight container and enjoy!
Notes
Can be kept for up to one month in an airtight container stored in a dry, dark and cool place.Do not refrigerate or freeze.