Line two large baking sheets with parchment paper or silpat mats. Fit a large piping bag with a small round tip (such as Wilton #10).
Heat a small saucepan of water over medium-high heat. Place a large heatproof bowl over the simmering water. Add the egg whites and sugar to the bowl and whisk continuously until the sugar has fully dissolved - about 5 minutes.
Transfer the egg white mixture to the bowl of a stand mixer fitted with the whisk attachment.
Whip the egg whites on medium-high speed until the egg whites reach stiff peaks. The meringue will feel dense and start to gather on the sides of the bowl.
Once the egg whites have reached stiff peaks, sift in the almond flour, powdered sugar, and cocoa powder.
Gently fold in the dry ingredients, forming a “J” shape with your spatula. Make sure to scrape all the way to the bottom of the bowl so the meringue is evenly mixed.
When all of the dry ingredients have been mixed in, gently smush the meringue against the sides of the bowl and fold it back together to deflate the meringue. Repeat the smush and fold process 2-3 more times.
Test the batter occasionally to see if it has reached the “lava stage”. If you can draw a figure 8 with the meringue without the stream breaking, its ready to pipe. If the meringue comes off the spatula in clumps or the stream breaks while drawing the 8, deflate the batter a few more times and repeat the figure 8 test.
When the meringue flows like lava, transfer it to the piping bag fitted with the round tip. Pipe 1.5”circles onto the silpat lined baking sheet. Immediately after you’ve finished piping the tray, hold it 6” off the counter and drop it to release any air bubbles. Drop the tray 5-6 more times, or until it looks like any large air bubbles have popped.
Set the tray aside and allow it to rest for 20-25 minutes, or until the macarons develop a skin. The macarons are ready to bake when you can touch them without any meringue sticking to your finger.
While the macarons rest, preheat the oven to 325F. I recommend using an oven thermometer when making macarons to ensure your oven is set to the correct temperature. Bake the macarons one sheet at a time for 15 to 16 minutes, turning the tray halfway through baking.
The macarons are finished baking when they come off the tray easily. Allow the macarons to cool on the tray before filling.