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. Add all of the powdered sugar and almond flour to the meringue. Gently fold the macaron batter, often scraping the sides and bottom of the bowl. Once it is all just combined (no powder remaining), equally separate the batter into two bowls.
Keeping the other bowl covered, add your gel/powder food coloring of choice to the batter you will first mix. 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 small/medium piping bag.
Repeat the last step with the remaining batter.
Cut the tips of each piping bag and place them into the large piping bag fitted with a round tip. Pipe the macarons onto your silicone mats/parchment paper, using your template as a guide.
After piping the macarons, 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 templates.
Allow the macarons to sit out at room temperature to dry for at least one hour. They will be ready to bake once the surface of the macaron is matte and dry to the touch. If it is a really humid day, it can sometimes take 2 hours for them to dry.
Preheat the oven to 325F. Place an empty baking sheet upside-down on the middle rack.
Place the baking sheet with the macarons on top of the upside-down baking sheet. Bake 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.
Remove the macarons and place on a wire rack. Bake the remaining macaron shells.
Allow macarons to fully cool before peeling them off the parchment paper or silicone mats.