Before you start, get all of your ingredients ready. Prepare a large piping bag, fitted with a large round tip. Set aside.

Also set aside as many piping bags as the number of colors you’d like to color your shells. I used 3 different colors.

Line two baking sheets with parchment paper or silicon mat.

I use a baking mat with the macaron template already in it. You can make your own or print it from the internet, and just place it under silicon mat, or parchment paper. I recommend using a silicon mat

Measure out all of your ingredients.

Sift powdered sugar and almond flour together. Set aside.

Place egg whites and granulated sugar in a heat proof bowl or in a double boiler. Over a pan of simmering water, whisk the whites and sugar until frothy and sugar completely melted. It will take a couple minutes. You can test by touching the mixture between your fingers, and if you feel any sugar granules just keep whisking mixture over the water bath.

Make sure the bottom of the bowl isn’t touching the simmering water.

Transfer mixture to the bowl of a stand mixer.

With the whisk attachment, start whisking mixture on low for about 30 seconds, then gradually start increasing speed to medium. Whisk on medium for one to two minutes, until mixture is white and starting to become fluffy. Raise speed to high for a few minutes until stiff peaks are formed. Best way to check this is to keep your eye on the whites. Once they get glossy and you start seeing streaks formed by the whisk, it might be time to stop.

Whisk until stiff peaks have formed. When you pull your whip up, the peak should form a bird’s beak shape, but shouldn’t be falling to the side, the peak should be stiff, forming a slightly curved shape at the top.

Pour powdered sugar and almond flour into stiff whites.

Start folding gently forming a letter J with a spatula.

Fold just until you don’t see any streaks of dry ingredients any longer. Once that happens, you can split the batter between the number of bowls correspondent to the colors you want to use in your batter.

I split my batter into 3 different bowls.

Work quickly, with each color, one at a time, folding the batter until ready, then transferring it to a piping bag. Move on to the next color and do this until the entire batter is ready.

It’s time to stop folding when the batter is glossy and has a thick and flowing consistency. There are several ways to test this, and you might have to have a couple failed batches before you get this right.

First, I pick up some batter with my spatula and try to draw a figure 8 with the batter that is dripping off the spatula. If you can form several 8 figures without the batter breaking up, that’s one indication that it might be ready.

There's another test you can do. I call it the Teaspoon test.

Grab a teaspoon of batter and spoon onto the parchment paper or silicon mat. Wait a minute to see how it behaves.

If the batter stays stiff, forming a point and doesn’t spread out a bit, I start folding a little bit more, about 3 folds.

Test again.

Once the batter spreads out a bit and starts to look glossy and smooth on top, on the parchment paper, I transfer my mixture to the piping bag.

You don’t want your batter to be too runny either. So be careful not to overmix. It’s always best to undermix and test several times until the proper consistency has been achieved.

This is the most important part about making macarons in my opinion.

Transfer each color to one piping bag. Then cut the tip of each piping bag. And place them inside of a large piping bag fitted with a round tip.

Applying equal pressure around the whole piping bag, start piping the macarons onto the baking sheet.

Once you’ve piped as many circles as you could, bang the trays against the counter a few times each. This will release air bubbles that are in the batter and prevent your macaron shells from cracking.

Let your trays sit for a while so the shells will dry out a little bit. I usually leave about 20-40 minutes, depending on how humid the day is. You’ll know they’re ready when you gently touch the surface of a macaron and it seems dry.

Pre-heat the oven to 325F.

Bake one tray at a time.

Bake for 4 minutes, rotate tray.

Bake for 4 more minutes. Rotate again.

I bake each tray for a total of 18-20 minutes rotating every 4 minutes.

When baked, the macarons will have a deeper color and formed feet. And they will be coming off the mat easily, and with a completely formed bottom.

Remove from the oven and bake the other tray.

Let the macarons cool down before proceeding with the filling.

Cream butter at medium speed in the bowl of an electric mixer for about 1 minute. With the mixer off, add all of the powdered sugar.

On low speed, beat the sugar and butter together. Once they are incorporated, turn speed to medium and cream for 1-2 minutes until very fluffy.

Add vanilla beat for another 30-45 seconds.

If necessary, add the milk. Only add 1/2 tablespoon of milk at first. Sometimes you may find that the consistency of the buttercream is already perfect and doesn't need any more liquid. If the buttercream seems too stiff, add a bit more of milk as necessary. If the buttercream seems too runny, add more sifted powdered sugar until you obtain a firm, but smooth and creamy consistency.

STORAGE: Store buttercream in the fridge for up to 1 week.

Place buttercream in a piping bag fitted with the tip of your choice.

Pipe a dollop of buttercream in the middle of the bottom shells.

Place top shell on top.

Let macarons mature in the fridge overnight before serving.

Macarons will store really well in the fridge for up to 1 week, or in the freezer for up to 2 months.