Preheat oven to 300 degrees Fahrenheit.
Separate 100g of egg whites (about 3 large eggs).
Beat egg whites until foamy with a whisk attachment for about 1 minute.
Add in ½ teaspoon meringue powder (optional) and 90 grams of granulated sugar in three increments, mixing on medium after every addition.
After all sugar is added, mix on medium/high for 5 minutes. It should have stiff peaks and be pulling away from the sides of the bowl.
Add in green food coloring and mix until combined.
Combine 130 grams of almond flour, 130 grams of powdered sugar and 1 teaspoon of egg white powder (optional) in a fine mesh stainer. Sift through and discard any larger chunks.
Pour the sifted dry ingredients into the whipped mixture stirring just enough to incorporate them.
Then, start gently folding the mixture to deflate it. Make sure to scrape the bottoms and sides.
When done, you should be able to scoop some with your spatula and have it ribbon off, then reincorporate into the mix in about 20 seconds.
Transfer batter to a pastry bag with a large roudn tip.
Add macaron template to baking pan.
Hold pastry bag about ½ inch above the template and squeeze slowly until the batter fills the inner circle of the template.
Once all rounds are filled, lift the baking sheet and hit it on the counter a few times to release air bubbles.
Allow batter to rest for at least 30 minutes. You should be able to touch the surface of the shell without any sticking to your finger.
Once they have rested, bake for 10 - 11 minutes. Set aside and allow to cool.