Before beginning: If you are a beginner, first read through the post and watch the video. Ensure all of your equipment (bowls, spatulas, beaters, etc.) are completely clean, dry, and grease free. Avoid using rubber, silicone, and plastic when whipping egg whites.
Line two or three cookie sheets with parchment paper and set aside.
Sift almond flour, powdered sugar, and cocoa powder into a medium-sized mixing bowl and whisk to combine. Set aside.
To a separate, large mixing bowl, add egg whites and, using an electric mixer, beat on medium speed until foamy (about 30 seconds).
Add cream of tartar and stir again (medium speed) for 30 seconds.
While mixing, add about 1 Tablespoon of granulated sugar and beat for about 30 seconds before adding the next Tablespoon. Repeat, waiting 30 seconds between additions, until all sugar has been added.
Once all sugar has been added, add vanilla extract, salt, (if using brown food coloring, add this here, too). Continue to beat on medium to medium-high speed until mixture reaches thick, fluffy, stiff peaks, meaning if you lift the beaters from the bowl, the peak that forms should hold its shape and not fold or shrink back in on itself.
Add approximately a third of the cocoa powder mixture to the meringue and use a spatula to fold until combined. Repeat with the next third of the mixture, then the last.
Continue to fold the batter, moving your spatula in sweeping motions, scraping down the sides and bottom of the bowl and cutting through the middle of the batter and turning your bowl as you go. Use your spatula to smoosh the mixture against the side of the bowl periodically to help deflate it. Continue to fold until the batter flows smoothly and falls from the spatula in a smooth ribbon. You should be able to JUST BARELY make a figure-8 with the batter without the meringue breaking.
Pour the batter into a large pastry bag fitted with a round tip (I like the Ateco 804).
Pipe batter into 1 ½" circles onto prepared baking sheets, holding the piping bag straight up and down and flicking your wrist at the end to complete the macaron. Space macarons at least 1 ½” apart.
Rap each pan very firmly on your countertop 4-5 times to release any air bubbles and preheat your oven to 325F (160C).
Let macarons rest until a skin forms on the surface (if you run the pad of your finger over the top it should feel dry and not sticky or tacky). This typically takes about 25 minutes in my kitchen, but may vary.
Bake one tray at a time in the center rack of your oven for 10-11 minutes, turning the pan around halfway through the baking time. When finished baking, the feet should look dry and if you lightly press down on the top of a macaron it shouldn’t give.
Allow macaron shells to cool completely before filling with chocolate ganache.
Chocolate Ganache
Place chocolate in a medium-sized heatproof bowl and set aside.
In a small saucepan, heat cream until steaming. Remove from heat and pour cream evenly over chocolate. Cover with aluminum foil and allow to sit, undisturbed, for 5 minutes.
Remove foil and whisk mixture until smooth.
Add butter, salt, and vanilla extract and stir until butter is melted and mixture is smooth.
Allow chocolate to sit at room temperature until firm, then transfer to a piping bag.
Pair off cooled macaron shells and pipe ganache onto the bottom of one shell before sandwiching with another similarly sized macaron shell.