Sift the almond flour and powdered sugar together. Repeat if necessary to remove all the clumps.
Use the mixer to whisk the egg whites into soft peaks.
Slowly add the granulated sugar while beating until stiff peaks form. This is where to add in the food coloring.
Gradually fold in half of the dry ingredients into the egg whites.Be careful not to squash the egg whites. Try to keep them fluffy.
Fold in the other half of the dry ingredients. Keep folding until all the ingredients are incorporated and the batter flows slowly to create ribbons that disappear into the rest of the batter in about ten seconds.
Put the batter into a piping bag, use the round piping tip. Pipe even circles about 1 1/2 inches onto the silicone mat. Tap the baking tray on the counter a few times to release the air bubbles.
Let the shells rest at room temperature for about an hour, until they form a skin, they will no longer be sticky when touched.
Preheat the oven to 300 F and bake for 15-18 minutes. Let them cool before removing them from the tray
To Make The Filling
Use the mixer to whip the butter and powdered sugar together until fluffy.
Mix the lemon juice in.
Assembly
Fill the piping bag with the lemon filling. Use the round piping tip again.
Pipe onto one of the macarons then sandwich it together with another.
Notes
You can add more or less lemon juice depending on your preference
I like to use the cooking scale to get a more accurate measurement to make the shells.
Don’t skip the resting step, they need to rest in order to rise properly.