Add the powdered sugar and almond flour to a food processor and process for about one minute, or until the mixture is well blended and the almond flour is ground down to a fine powder.
Sift the mixture into a bowl, discarding any pieces that don’t go through the sift. Set aside.
Wash and completely dry your stand mixing bowl and whisk attachment. Briefly rub down both with lemon juice to ensure there is no fat or oily residue on the equipment.
Add the egg whites and begin to whip on medium-low for about a minute.
Add the pinch of salt when the egg whites get foamy and bring up the speed up to medium-high until the eggs reach soft peaks – this is when the meringue makes deep curls when you take out your whisk and point the whisk upward. This should take about 3 – 5 minutes.
Add the granulated sugar once it reaches soft peaks and beat for about 2 minutes longer, or just as it is about to reach stiff peaks (stiff peaks happen when the meringue points straight up and does not curve when the whisk is pointed upward).
Turn off the mixer and pour in the almond four mixture, food coloring, and vanilla.
Scrape the bottom and sides of the bowl, folding the mixture onto itself. As you do this, also pull up some of the batter into the air to see if it drizzles down in a ribbon.
Once it does this, check how long it takes for the ribbon to incorporate back into the batter. It should slowly flow back into the batter like magma. If the ribbon dissolves back into the batter within a few seconds, you've reached proper macronage.
As soon as you reach the desired consistency, immediately stop mixing and set the batter aside, uncovered, for 30 minutes.
While the batter rests, preheat the oven to 325°F.
Line two baking sheets with baking mats and fit a piping bag with a round piping tip. I do not recommend not using a tip as you will not have as much control.
Fill the piping bag halfway with the macaron batter and begin to pipe the batter,
Once the macarons are piped, tap the baking sheets on your counter two or three times to remove air bubbles. Take a tooth pick to pop any small bubbles you may find.
Leave the macarons to rest for at least 45 – 60 minutes.
Bake the macarons one sheet at a time on the middle rack for five minutes, then turn the baking sheet 180 degrees and bake for another 5 minutes.
Allow the baked macarons to cool on the baking sheet for about 5 minutes before transferring to a wire rack to cool completely.
Once both sheets are baked and the macarons are cool, frost half of the shells and top with the remaining shells.
Store in an airtight container.
Notes
Make sure you don't let any yolk go into the egg whites as it will ruin the recipe.
Completely wash and dry your bowl and whisk you use to whip your egg whites. I like to rub mine down with lemon juice as well because it cuts out any remaining fat in the bowl or whisk.
If your ribbons meld back into the batter almost immediately, your batter is too thin.
Take your time, have fun, and remember, it will still probably take a few tries before your macarons are technically perfect, but they will still be delicious!