Using a sheet of parchment paper.; draw 24 one-inch circles on the paper, spacing them at least half an inch apart. You can use the wide end of a large pastry tip as a template for the circles. Lay this paper on a sheet tray with the drawn circles facedown or use a macaron mat.
Preheat the oven to 300 degrees.
Place the almond flour, confectioner's sugar, cinnamon and cocoa powder in your food processor. Process until you have a fine powder. Sift the mixture through a sieve twice.
Melt the chocolate in a heat resistant bowl, placed over a slowly simmering bain-marie (or in a microwave) until warm.
Place the egg whites in a large, clean bowl. Using a handheld mixer or a stand mixer with a whisk attachment, beat on high speed until they are foamy.
Gradually add the sugar to the egg whites. Add the vanilla extract, and beat the whites on high speed until you have stiff, glossy peaks, about 1 minute.
Pour the melted chocolate into the egg whites. Use a spatula to roughly incorporate it.
Add half of the sifted almond mixture to the whipped egg whites. Fold it in gently, using a wide spatula to scoop up from the bottom of the bowl.
Add the remaining almond mixture and mix it lightly in a circular motion.
Once the flour has been incorporated, press and spread out the batter against the bowl's sides. Scoop the batter from the bottom, and turn it upside down. Repeat this step about 15 times.
If this step, known as macaronnage, is done less than 10 times, the macarons will lack luster. If this step is done more than 20 times, oil stains may remain on the pastries' surface after they are baked.
When the batter becomes nicely firm and drips slowly as you scoop it with the spatula, it is done.
Set up a piping bag fitted with a 1/4-inch round tip. Fill the piping bag with the batter until it is about 1/2 full.
Squeeze the batter into the center of your circles on the parchment paper or mat. The batter tends to spread after being piped, so don't fill the circles in completely.
Tap the sheet tray firmly against the counter. This helps the macarons hold their rounded shape and helps to form the little foot when they bake. It also help get rid of any air bubbles in the dough.
Allow the circles to dry at room temperature, uncovered, for about 15 minutes. A slight crust should form on top of the macarons.
If the batter does not stick to your finger when you touch them, the drying is complete. If they are still a bit wet, allow them to dry a little longer.
Nest the tray of macarons onto another sheet tray. Doubling the trays helps prevent the macarons from over browning on the bottoms.
Bake the macarons until they are slightly crisp, 14-16 minutes. If the insides of the macarons are still soft, lower the temperature and cover the try with foil. Continue baking for an additional 2 to 3 minutes. I tap the macaron from the side gently with my finger. There should be no movement between the top and the foot of the macaron when they are fully baked.
Allow the baked macarons to cool completely. After they are cool, fill the macarons with the chocolate ganache.