Pour the aquafaba into a small saucepan and simmer on medium heat to reduce the liquid to 1/2 cup (120 ml, about 12-15 minutes). Pour into a medium bowl and aside to cool completely to room temperature.
In a small mixing bowl, add the almond flour, matcha powder, salt and 3/4 cup (165 g) of the sugar. Whisk to combine.
Add the cream of tartar to the cooled aquafaba along with the almond extract and vanilla extract. Using a hand blender, beat on high until stiff peaks form, about 8 minutes. (You will know it's ready when you can turn the bowl upside down and nothing moves).
Sprinkle the dry ingredients into the aquafaba mixture, 1/2 cup at a time, and fold into the dough until a thick dough has formed. Compress the dough together into the bottom of the bowl and place in the fridge to cool for 15 minutes. (This allows for easier rolling).
While you're waiting for the dough to cool, place the oven racks in the upper and lower thirds of the oven. Preheat the oven to 325F/160C. Line two baking sheets with parchment paper.
Prepare two small plates to sugar coat the cookies: On one plate add 1/4 cup of sugar (55 g) and on the other plate add 1/3 cup of icing sugar.
When the dough is ready, scoop approximately 2 tablespoons and roll the dough into a ball using the palm of your hand. Then, roll the dough ball in the sugar to coat with a thin layer, followed by the icing sugar to coat. Place the cookie ball onto the prepared baking sheet. Repeat until you've used up all the dough (recipe should make 18 balls split between two sheets, spaced about 2 inches apart).
Use the flat bottom of a glass to compress each ball to about 3/4 inch thick. It's okay if you get some splitting at the edges of the cookies, it actually adds to how they look.
Bake the cookies until very lightly brown on the edges and the tops are cracked, 20-22 minutes. Switch the pans halfway through for an even bake. Let cool for 5 minutes, then transfer to a wire rack to cool completely.