Before you start, get all of the ingredients ready. Prepare a large piping bag, fitted with a large round tip.
Line two baking sheets with parchment paper or silicone mat.
I use a baking mat with the macaron template already in it.
Measure out all of the ingredients.
Sift the powdered sugar and almond flour together. Set aside.
Place the 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, whisk the mixture on low speed and gradually increase the speed to medium, or medium-high, and continue to whip until the meringue achieves stiff peaks.
Once the egg whites 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 be stiff and shooting straight up, with possibly a slight bend at the top, but not bending to the side.
Pour the sifted powdered sugar and almond flour into stiff whites.
Start folding gently forming a letter J with a spatula. Add the food coloring at this point, if using.
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.
First, pick up some batter with the 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, fold 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 it means the batter is probably ready.
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.
Transfer the batter to a piping bag.
Place the piping bag directly 90 degrees over the center of each macaron template. Apply gentle pressure and carefully pipe for about 3 seconds, and then quickly pull the bag up twisting slightly.
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 the macaron shells from cracking.
Let the 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, and doesn't stick to your finger.
Pre-heat the oven to 300°F.
Bake one tray at a time.
Bake for 5 minutes, rotate the tray.
Bake for 5 more minutes, check if it needs to be rotated again. You will know if it needs to be rotated again depending on how the macarons are baking. Take a look at them, if one side seems taller than the other, maybe you have to rotate the tray again.
Bake each tray for a total of about 15 to 20 minutes.
When baked, the macarons will have a deeper color and formed feet. If you try to move a macaron, it shouldn’t feel jiggly. If the macaron is still jiggly, keep baking.
Remove from the oven and bake the other tray.
Let the macarons cool down before proceeding with the filling.
Blueberry Jam
Mix the blueberries, maple syrup (or sweetener) and lemon juice in a small pot. Bring to a boil over medium heat, cook, stirring, for about 5 minutes. Use the spoon to break up the blueberries as you stir.
Mix cornstarch and cold water in a small bowl.
Once blueberries have boiled and reduced a bit, add cornstarch and water to the pan.
Bring back to a boil, stirring constantly, until mixture is thickened.
Let jam cool. Cover it with plastic wrap and place it in the fridge.
You may process the jam in a small food processor to make it smooth if you want to, or strain it. I like my blueberry jam to be a bit chunky, so I usually leave it as is, though sometimes I do process it on my blender cup to make it smooth.
Vanilla Buttercream
Sift the powdered sugar. Set aside.
Cream the 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 in.
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 extract and beat for another 30-45 seconds.
If buttercream is too stiff, add a bit of milk or water to make it a bit softer. And if buttercream is too runny, add a bit more sifted powdered sugar.
How to assemble
Pipe a circle of buttercream around the edges of the macaron, in a way that you have a little hole in the middle. Fill the little hole with a bit of blueberry jam. Don’t overfill it. Place another shell on top.
Storage
These Blueberry Macarons will be at their best up to 4-7 days in the fridge.
I don’t recommend freezing macarons with jam fillings, since they will often turn soggy because of the jam.
Notes
Jam: If you don’t want to make your own jam, that’s ok. You can use store-bought. You will need about 1/4 cup of jam. If you have leftover jam, keep it in the refrigerator and use it within 1-2 weeks. Spread it on some toast, or my favorite way is to add to a yogurt bowl, with some fresh fruit (and granola sometimes).Food coloring: Make sure to use gel food coloring. I use Wilton Color Right Performance Food Coloring Set. If you are a beginner macaron baker, I recommend going easy on the food coloring, as it can alter your batter a lot, and it can take extra mixing time, specially if you continue to add the food coloring as you do the macaronage.Scale: Please use a scale when measuring the ingredients for accuracy.Macaron amount: it will vary greatly depending on how big you pipe the shells, and on how runny or thick the batter is.Baking time/temperature: Baking time and temperature will vary according to your own oven. I recommend experimenting with your oven to find out the best time, temperature, position of the baking tray.Oven thermometer: Make sure to have an oven thermometer to bake macarons. It’s one of the most important things about making macarons. Home ovens aren’t accurate at all at telling the temperature, and even a slight 5 degree difference can make or break your whole batch.Tray rotation: Lots of bakers don’t have to rotate the trays 180 degrees in the oven every 5 minutes, but I do have to with my oven, or I will get lopsided macarons. Please adjust this according to your oven.