Have all of your ingredients measured and ready to go. Line a baking sheet with parchment paper or a silicon baking mat. No need to turn the oven on yet, since the macaron shells will have to sit for a while before baking.

In a large bowl, mix the almond meal, powdered sugar, and matcha powder. Sift into another large bowl to aerate the mixture and remove any large lumps (they will affect the texture of the macaron shells).

In yet another large bowl, beat the egg whites with an electric hand mixer or stand mixer on low speed until frothy. Then, add the cream of tartar and whisk on medium high speed until they form soft peaks. Now, begin to add the granulated/caster sugar a bit at a time until stiff peaks form (when you lift the whisk out of the bowl, the whites will stick to it).

Using a rubber spatula, gently fold in the almond/powdered sugar/matcha mixture a bit at a time. Once all the dry mixture has been incorporated into the egg whites, it should have a lava-like consistency – thick, but flowy.

Spoon the batter into a pastry bag with a plain round tip. If you don't have one, you can use a ziplock bag and cut about 1/8"off of one corner to make your own pastry bag. Pipe 1.5" circles onto the parchment-covered baking sheet, leaving about 1" of space between each macaron shell. Once you have piped all the circles. Pick up the baking sheet and let it drop a few inches onto your counter to release any air bubbles. Do this two or three times.

Let the macaron shells sit at room temperature until the tops lose their shine and become dry to the touch. This will vary a lot depending on the humidity in your kitchen, anywhere from 15 minutes to over one hour, so just keep an eye on them. Now is the time to preheat your oven to 300°F.

Bake for 10 to 20 minutes, depending on your oven. When they are done the bottoms should be lightly brown, and they will have developed signature macaron "feet," the crinkly edge on the bottom (see photo above). The top should be firm to the touch. Mine have taken anywhere from 10 to 16 minutes. I sit and watch them for the last few minutes to make sure they don't get too toasty. While they are cooling, you can make the filling.

To make the buttercream filling, beat the butter and extract until fluffy, then gradually add the powdered sugar, mixing until smooth.

Once the macaron shells are cool, pipe some buttercream onto half of them, and top with the remaining shells. Bon appetite!