In a medium bowl, add the powdered sugar, almond meal, and cocoa powder. Sift them together in a large bowl. Set aside.
In a small bowl, add the sugar. Set aside.
Prepare a piping bag with a round tip, a spatula, and a baking tray flipped upside down with parchment or silpat lining the top.
In a mixing bowl, add the room temperature egg whites and begin whipping on medium with the whisk for 30-40 seconds, or until the whites start to get foamy.
When the whites are foamy add the cream of tartar and keep whipping. Begin sprinkling the sugar into the whites by the spoonful. When all of the sugar is added increase the mixing speed to high and whip for 3-4 minutes, or until the whites reach stiff peaks.
Using the spatula, add the whites to a large bowl and add ⅓ of the dry mixture to the bowl. Gently deflate some of the whites while folding in the dry ingredients. Once it is all incorporated, add the second ⅓ of the dry mix, continue to fold until all of the dry ingredients are incorporated.
Begin the 'macaronage' by scraping the batter against the sides of the bowl and then back into the middle. Stop mixing when the batter falls from the spatula and you can make a figure 8 without the batter breaking.
Fill the piping bag with the batter and pipe rounds directly above the pan. Once the pan is filled, rap the pan against the counter on all sides to pop any air bubbles that might be inside the shells. You can use a tooth pick to pop any of the bubbles that come to the surface.
Preheat the oven to 300.
Allow the macarons to sit on the counter to form a 'skin'. This can take anywhere from 15-40 minutes, depending on the humidity. They should look matte and not shiny and you should be able to touch them without leaving a mark when they're ready.
Bake the shells for 13-14 minutes, or until you touch the top of the shell and it doesnt move.
Allow to cool on a wire rack completely before filling.