Sift the almond meal and powdered sugar together into a large bowl. If there are any large pieces of almond meal, discard. Set the bowl aside.
Add your room temperature egg whites to a stand mixing bowl with the whisk attachment. Begin whipping on medium speed (3-4) for 1 minute until foamy.
When the whites are foamy, add the cream of tartar.
After adding the cream of tartar, start sprinkling in the sugar. Do not add too much at once or it will deflate your egg whites! Once all of the sugar has been added, increase the speed to medium high (5-6) for 6-7 minutes, or until the whites get glossy, shiny, and hold a stiff peak!
Using a rubber spatula, add the whites to a large bowl. Sprinkle in ⅓ of the dry ingredients and gently fold them into the whites. Try not to fold too aggressively, you want to preserve as much air as possible in this step. Continue adding the dries in thirds until all of it has been added.
Then use the spatula to scrape the batter against the sides of the bowl. Every few scrapes test to see if the batter is ready. Pick up some of the batter and let it flow back down into the bowl. If it flows slowly and looks like ribbons, try to form a figure '8' . If you can make a figure 8 without the batter breaking, its ready!
Fill your piping bag with a #12 round tip. Better to have a smaller tip than a larger one! Flip a sheet pan upside down and lay down your parchment paper or silicone baking mat. Pipe directly from above into desired size.
Grab your pan and firmly tap it on the counter. Make sure you tap all sides of the pans. This will release any air bubbles and bring them to the surface. Use a tooth pick to pop any bubbles that come to the surface for the smoothest shell possible.
Let them sit at room temperature until they form a skin. You should be able to touch the top of the shells with your finger and it shouldn't leave a mark.
Bake the macarons at 275-300 for 13-14 minutes. Do not open the oven too soon. 10 minutes into their baking, open the door and touch the top of the shell. The top should not move from the feet when they're ready!
Allow to cool completely on a wire rack before removing.