Line a cookie sheet with parchment paper and prepare ingredients ahead of time.

Sift almond flour to eliminate any large chunks. You want to end up with 75g, so add more to take place of any you need to discard.

Combine almond flour, powdered sugar, and cinnamon, then sift together.

In a stand mixer, beat egg whites on high. As egg whites become foamy (~30 secs), add a pinch of Cream of Tartar.

Add caster sugar slowly (over the course of 10-15 seconds) as you continue beating on high.

Continue beating on high until stiff peaks form. (About 2 minutes.)

Remove bowl from mixer and fold in half the dry ingredients. After the first half has been incorporated, fold in the second half.

Slowly continue folding — you want to make sure everything is incorporated. You don't want to be too aggressive, but you also don't want to under-mix. The consistency you're looking for is thick and lava-like. It should flow slowly down the sides of the bowl.

Transfer the macaron batter to a piping bag and pipe 1.5″ rounds onto the parchment-lined cookie sheet. After piping, rap the cookie sheet on the countertop a few times to remove air bubbles (lift it a few inches and drop it). Let the macaron rounds sit for 30-45 minutes.

Preheat oven to 325°F. Bake macarons for about 10 minutes. Ovens are finicky, so you have to experiment for yourself. (I bake mine for 12 minutes.)

Remove from the oven and transfer the entire parchment sheet to a cooling rack. Once they’ve cooled, carefully remove the macaron shells from the parchment.