• First, prepare all your ingredients, parchment paper or silicone liners, baking trays, and the piping bag. Then, sift almond flour with powdered sugar into a bowl and whisk to combine. Sugar might form lumps even after sifting but whisking will help break those lumps.
• Then, take a metal bowl and wipe it with a little bit of vinegar. Add the egg whites and start beating them on low speed. Once the eggs start foaming wait until the foam becomes thicker but not too thick yet. At that point, start adding granulated sugar to the bowl 1 teaspoon at a time. Let the mixer go 5 circles, then add 1 teaspoon more. You can speed up adding the sugar after you added at least half of it.
• Once all sugar has been added, you can increase the mixer speed. Stop frequently to see how thick egg whites are. You want them to be stiff but not entirely stiff. The tip of the mixture should lean to the side, not stand up straight. You know you beat the egg whites too much if when you start folding the flour egg whites break apart into lumps.
• Once egg whites are ready, add ⅓ of the dry ingredients to the bowl and carefully fold it into the egg whites using a rubber spatula. You need about 7 folds until you are ready to add another ⅓ of the flour.
• Once all flour has been added, continue folding until the batter flows off the spatula and you can slowly draw number 8 with the batter without it breaking the line. Be careful not to overmix the batter. If you mix it too much, it will lose air bubbles and become very thick so that it won’t flow at all. Once the consistency is right, add the batter to the piping bag using a rubber spatula.
• It is important that you turn your baking trays upside down and place parchment paper or silicone mats on top of it. Now, to make the shells the same size you need to use a macaron pattern. Some silicone mats have that but you can also print out the pattern and place it under the parchment paper.
• Bring the pipe close to the surface and pipe until the desired size. Then, stop pushing the bag and make a quick circular motion to separate the bag from the macaron. This will help avoid tips following the bag’s movement as you move on to the next shell.
• Once all shells are piped, tap the baking trays against the table about 10 times to get rid of the bubbles inside the shells. Then, take a toothpick and poke any visible bubbles that did not break on their own.
• Now, rest the shells for 30-40 minutes until the surface doesn’t stick to your finger as you touch it.
• After 20-30 minutes of resting the shells, start preheating the oven to 300F/150C. Use an oven thermometer as most ovens are not precise with their temperatures. Mine, for example, has to be heated to 275F/135C in order to reach 300F/150C on a thermometer.
• When the oven is ready, bake the first batch in the middle of the oven for 12-14 minutes. The shells should be firm to the touch when ready. If you feel a little wobbling as you press on the shell, keep baking for another minute and check again. It is better to overbake your macarons a little than underbake. It is easy to make them soft later!
• It is very important to let macarons cool completely before transferring them. Once ready, use a metal spatula to carefully separate the shells from the surface.

Buttercream

• You can make buttercream while macarons are resting, baking, or cooling. To make dulce de leche buttercream, you will need dulce de leche and room-temperature butter. I like to add ½ tablespoon of coffee grounds for extra flavor. Beat the butter with a mixer for at least 5 minutes stopping to scrape the sides from time to time. The butter should become light, fluffy, and creamy. Patience is key!
• Then, add dulce de leche with coffee grounds and mix until incorporated.
• Fill the piping bag with buttercream and pipe on a macaron shell, then place the other one on top. Repeat until all macarons are ready. Then, let macarons age in the refrigerator for 24 hours before eating!