Preheat oven to 300 degrees

Combine powdered sugar and ground almonds and sift. Set aside.

In the (clean, dry) bowl of an electric mixer, whip the egg whites with salt on medium speed until foamy. Increase speed to high and gradually add sugar. Add cinnamon and continue to whip until stiff peaks form, and the mixture is shiny.

In a large clean bowl add whipped eggs. Add sugar/almond mixture on top and gently fold until just combined. Do not whisk, do not hurry, and do not mix any more than you have to to combine.

Prepare a pastry bag with a large circle pastry tip. Stand it in a tall glass for easy loading. Line baking sheets with parchment paper and pipe small discs, around 1.5 inches in diameter across. Let macarons rest 30 minutes at room temperature before baking.

Bake on a lower rack in the oven for 12 minutes. Let cool at least 30 minutes before gently peeling off the parchment paper.

Grasp one disc and pipe or spread the chocolate buttercream, sandwiching with another macaron. Repeat until all sandwiches are assembled.

Melt chocolate and drizzle over shells (optional). I suggest looking at the pictures from these two posts, to get a better idea of what the macaron process making looks like before diving in for the first time.

Cream butter with an electric mixer. Sift together the powdered sugar and cocoa powder.

Add sugar mixture to butter and cream until buttercream has formed. Add 1 – 2 TBS if needed to reach desired consistency.