Preheat the oven to 300ºF. Pulse your almond flour, salt and confectioners’ sugar in the bowl of a food processor four times, for four seconds each time. (If you do it for too long the mixture will get pasty.)
Sift your dry ingredients over a piece of parchment paper. Make sure the holes of your sifter are not too large or it will result in lumpy macaron tops!
Place your powdered egg whites, granulated sugar, cream of tartar and aged egg whites in the bowl of your electric mixer. With a hand whisk, incorporate until everything is combined and a little frothy. Then attach the bowl to the mixer and whisk on medium-high speed until glossy stiff peaks form (about 8-11 minutes).
A good test to check if your meringue is ready, is to hold the bowl upside-down. If your meringue doesn’t slide or move, you are ready to go. You can also tell your meringue is ready when the whisk leaves deep tracks in the bowl when rotating.
With your spatula, fold the dry ingredients into the meringue until you reach what we like to call the “unique macaronnage stage.”
It is important to fold the different components just enough, but not too much, or the macarons will crack. To make sure that you have reached the right point, once the ingredients appear combined, lift some of the mixture a few inches above the bowl with the spatula. If it retains a three-dimensional shape, fold it again. When folded just enough, the mixture should fall right back into the bowl, with no stiffness, in one continuous drip.
If you are adding food coloring, make sure to add when the dry ingredients appear to be just incorporated.
Pipe the macarons 1 1⁄2 inches apart on a silicon baking sheet. Slam the baking sheet onto a flat and stable surface to remove the excess air (slam six times, from six inches above the table). If you like, you can dip your finger in water and smooth the tops even more. Place a second baking sheet underneath the first and pop them in the oven -- this helps keep the macarons from burning.
Next, set the tray aside for one hour, or until the skin forms. This helps form the feet.
Once your skin has formed, place macarons in the oven for ten minutes. (You may need to add a minute or two depending on how large you piped your shells. I make mine two inches, and bake the macarons for ten minutes at 300º).
To test if the macaron is done, carefully try and lift one macaron off the baking sheet. If it just lifts, but sticks a little, your macaron is ready to go.
Cool completely before removing and filling. If the macarons darken too quickly, put a wooden spoon in the door of the oven to prop it slightly open. If you overcook your macaron, don’t fret. Overcooked is better than undercooked -- undercooking leads to sunken tops. If you have trouble removing the macarons from the baking sheet, try placing a few drops of water under the silicon mat. If that still doesn’t work, place the macarons in the freezer for fifteen minutes. They should pop right off.