In a medium bowl, mix the sifted almond flour and powdered sugar.
In a small bowl, combine granulated sugar and cream of tartar.
Pour the egg whites into the bowl of a stand mixer. Set up a stopwatch to time how long to whip the meringue. 0:00 - 4:00 minutes: Mix on medium-low for 4 minutes (Kitchenaid speed 4) until egg whites are foamy and white.4:00 - 9:30 minutes: Turn the mixer to medium speed (Kitchenaid speed 6). Add a third of the granulated sugar and cream of tartar mixture. After 30 seconds, add another third. After another 30 seconds, add the last of the granulated sugar and cream of tartar mixture. Keep mixing at medium speed until you have reached a total of 9:30 minutes. The meringue should transform from white and foamy -> white soft peaks -> white, glossy stiff peaks that balls up onto the whisk. If not, keep mixing at 20-second intervals at Kitchenaid speed 8 until it is. You can add the brown food coloring towards the end of making the meringue or when you add in your dry ingredients. Add all of the powdered sugar, almond flour, and cocoa powder to the meringue. Gently fold the macaron batter, often scraping the sides and bottom of the bowl.
Fold the batter until it reaches a thick, glossy consistency and flows off the rubber spatula into ribbons. To test if it is ready, allow the batter to flow off the spatula and into the batter. If the ribbons do not melt into the rest of the batter after 30 seconds, continue folding. Be careful not to over mix. When it passes this test, transfer the batter to the piping bag.
Pipe the macarons onto your silicone mats/parchment paper, using your template as a guide.
After piping the macarons, remove the templates and tap the trays against the counter a few times. If there are bubbles on the surface, you can use a toothpick or cookie scribe to pop them. Popping the air bubbles helps stop them from cracking when being baked. Remove the templates.
No-rest method if you have an airbake insulated baking tray: Bake macarons at 325°F/162°C for 15-20 minutes, rotating halfway through. To test if they are done baking, gently push the side of one shell. If it wiggles on the sheet, they need to be baked longer. If you do not have an insulated baking tray: Allow the macarons to sit out at room temperature to dry for 30-60 minutes, or until the macarons are dry to the touch and the batter does not stick to your finger. If it is a really humid day, it can sometimes take 2 hours for them to dry. Once they are set, bake macarons at 325°F/162°C for 15-20 minutes, rotating halfway through. To test if they are done baking, gently push the side of one shell. If it wiggles on the sheet, they need to be baked longer. Allow macarons to fully cool before peeling them off the parchment paper or silicone mats.