2/3 cup almond meal or ground almonds
1 1/2 cups powdered sugar
3 large egg whites, room temperature and preferably aged up to 3 days
5 tablespoons granulated sugar
1 teaspoon vanilla extract
Preheat the oven to 280ºF, and position 2 racks in the lower section of the oven. Line 2 rimmed baking sheets with parchment paper. If you have time, draw 1-inch circles on the back of each sheet, spacing the circles at least 1/2-inch apart.
If your almond meal is very coarse, grind it with the powdered sugar in a food processor until fine. Sift the almond meal-powdered sugar mixture twice through a mesh sieve.
Place egg whites in the bowl of a stand mixer (or use a hand mixer), and begin to beat on medium-high. When the eggs are frothy, gradually add granulated sugar 1 tablespoon at a time until fully incorporated. Continue to beat the egg white mixture until glossy and stiff peaks form when you lift the beaters. Gently stir in the vanilla extract. Be careful to not overbeat the meringue (e.g., the meringue takes on a clumpy texture).
Add half of the sifted almond mixture, and gently fold it into the meringue using a flexible silicone spatula. Lift from the bottom, up around the sides, and toward the middle, being careful to not over agitate the meringue and lose too much air. Once the almond mixture is predominantly incorporated, add the second half and repeat the folding motion.
When the almond mixture is just incorporated, you will need to transform the batter into the appropriate texture. Using the flat of the spatula, "punch" down into the center of the batter, then scrape more batter from the sides to the center, and punch again. You will need to repeat this 10-15 times (or more, depending on your arm strength and the beginning texture of your batter) until the batter slowly and continuously drips back into the bowl when you scoop it up with the spatula.
Punch the batter a few times, check the consistency, then punch a few more times, etc. Do not make the batter too runny or the macaroons won't rise as they should, and you could end up with oil stains on the surface.
Pour batter into a pastry bag fitted with a 0.4-inch tip. In a pinch, you can also use a gallon-size Ziploc bag: just snip a teeny bit from one of the bottom corners. Twist and clip the top of the bag to avoid overflow. On your prepared baking sheets, pipe out 1-inch rounds in the circles you drew (remember to draw the circles on the back side of your parchment).
Holding the baking sheet in both hands, rap each baking sheet firmly on the counter two or three times. This smooths out the tops and helps form the "pied" or frilly foot on the bottoms of the macaroons. Allow the piped macaroons to dry, uncovered, for at least 15 minutes. The macaroons should form a very thin, smooth crust where, if you tap it lightly with your finger, the batter will not stick to your finger. If after 15 minutes, the batter is still sticky, let it dry longer.
Place both baking sheets in the oven and bake for 15-18 minutes. After the first 2 minutes, open the oven to allow any excess humidity to escape. Halfway through, swap oven racks and rotate the sheets for even baking. The macaroons are done when they are baked all the way through and the shells are just hard. Take care to not under bake (insides will still be mushy) or over bake (tops will begin to brown). Remove them from the oven, and cool on baking sheet placed on a wire rack.
When fully cooled, assemble the macaroons with your choice of filling. The assembled macaroons can be stored in an airtight container in the refrigerator for up to one week.
Basic Macaroon Buttercream Filling
7 tablespoons unsalted butter, softened
2 egg yolks
1/4 cup granulated sugar
3 1/2 tablespoons milk
1 teaspoon vanilla extract
Just like the basic macaroon recipe, the basic buttercream filling recipe can be customized with endless flavors and colors. For options, try jams and preserves (or even Nutella) straight out of the jar, or whip up a quick chocolate ganache for a decadent spin on the macaroon.
Cut butter into pieces, and mash with a spatula until the consistency resembles mayonnaise. In a small bowl, whisk the egg yolks, then add the granulated sugar, and whisk until the mixture lightens to an off-white and you can no longer see the granules of sugar. Add the milk, and whisk to combine.
Pour the egg mixture into a small saucepan, and heat over low heat, whisking frequently to ensure that the mixture does not curdle or scorch. Cook until the mixture becomes thick and custardy, like pudding.
Pour the egg mixture back into its bowl, and whisk constantly until it returns to room temperature. Whisk in the butter in three batches, add the vanilla, and stir until smooth and all ingredients are fully combined. Pipe or spread onto one macaroon half and sandwich between the other.