Place your dry ingredients (almond flour, powdered sugar, and salt) into your food processor. Process for 5-second increments, three times. Shake the container as needed to ensure even mixing.
Place your strainer over a large bowl.
Sift the almond flour mixture to remove any large bits of almond. If you have to remove a lot, make sure to add the same amount of almond flour back in so that your batter ratio is not thrown off.
Place your egg whites, cream of tartar, and meringue powder (optional) into the bowl of your stand mixer with the whisk attachment attached.
Begin whisking your egg whites on medium speed until you reach soft peaks. Medium speed will produce smaller, stronger air bubbles than whipping at high speed.
Sprinkle in the granulated sugar slowly while whisking on slow until it's all added and continue whisking on medium until you reach stiff peaks.
Add ⅓ of your almond mixture into your meringue and fold together by scooping up under your batter, running along the side and bringing the batter up and over the top. Rotate the bowl and repeat.
Add in your food coloring, vanilla, and salt.
Continue folding until the batter flows off the spatula in a "V" and sits on the top of the batter for a few seconds before it dissolves back into the batter.
Another test you can do is to firmly bang your bowl onto the counter to see if the batter settles into itself. If it does, it's ready. If it doesn't move it still needs more mixing.
Prepare your piping bag with a #12 round piping tip by cutting the end of the piping bag off and inserting the tip into the bag.
Twist the piping tip and bag together to seal the bottom of the piping bag and then press the bag into the tip so that the filling does not leak out of the piping bag.
Fold the top of the piping bag down over your hand and scoop the macaron batter into the piping bag with a rubber spatula. Or you can place the piping bag into a tall glass so both your hands are free.
Lay the bag flat on the counter and push all the batter to the bottom of the piping bag so there are no air bubbles and then twist the top to prevent leaking. Tie the top into a knot if desired.
When ready to pipe, pull the piping tip out and move the batter down into the piping tip by squeezing the batter gently. Pro-tip: When you are not piping, hold the piping bag straight up to prevent leaking. When ready to pipe turn the bag over and immediately begin piping.