Using a fine-mesh sieve, sift the almond flour and the powdered sugar into a mixing bowl. Use a spook to help push the almond flour through. Do this one time, or twice for an extra fine mixture.
In a mixing bowl with a whisk attachment, beat the egg whites with the cream of tartar until soft peaks form.
Next, add in the superfine granulated sugar and vanilla extract and continue to beat until stiff peaks form. You don’t want to overbeat, but as soon as you can turn the bowl upside down and the mixture stays in the bowl, that’s when it’s done. You can stop beating after that.
Then you’ll fold in the almond flour/powdered sugar mix and add in a few drops of food coloring into the stiff egg whites. We’re using green to make Frankensteins!
Continue folding until the color is green and the ingredients are blended.
Add the mixture into a large pastry bag, fitted with a round tip.
Pipe the macarons onto a cookie sheet lined with a Silpat, Macaron Silpat or if you only have parchment paper that will work too. Although, we highly recommend using a Silpat for best results.
Pipe about 1 1/2″ circles onto at the lined cookie sheet. Space them about 2″ apart.
Once all of the cookies are piped onto the cookie sheet. Tap the cookie sheet onto the table to release air bubbles. Do this about 10 times.
This next step is SUPER important! The cookies MUST rest for 30 minutes to 1 hour before baking them in the oven. Let them sit on the counter for at least 30 minutes, although 45 minutes to 1 hour is even better. If you skip this step the cookies will not bake to the perfect round perfection they are supposed to. They will be a completely different shape. Do not skip this step.
Once the cookies have had time to rest, preheat the oven to 300 degrees Fahrenheit.
Bake for 15 minutes, so the cookie is well risen and you can see that little edge on the bottom. Since everyone's oven temperatures vary as well as locations, etc. make sure you’re always checking on your cookies. Check them after 10 minutes and continue checking until they’re done.
Just simply turn your oven light on to see how they’re doing.
Once they’re done, remove them from the oven and let them sit for 5 minutes. Then transfer them to a cooling rack to cool before adding frosting or design.
Continue making the batches of cookies, letting them rest before baking until the batter is gone.
Once the cookies are all baked, make a batch of buttercream frosting to make a macron sandwich cookie. We used this recipe and added the same green dye we used for the cookies.
Pipe the buttercream onto the bottom of one cookie and then add another cookie to the top.