Macarons with Lemon Buttercream Filling

Make the Macarons:
In a food processor, pulse together the almond flour and the powdered sugar. Add in 2 egg whites and process until smooth (the texture will be like almond paste).

Add in food coloring of your choice and continue processing until the color is all blended in. Put the mixture into a large bowl and set aside.

In a saucepan bring the water and sugar to a boil and cook for about 15 minutes, or until a candy thermometer reads 110 degrees-Celsius.

In the bowl of your electric mixer beat the remaining 2 egg whites until soft peaks form. Slowly drizzle in the hot syrup and continue beating until firm peaks form and the meringue has cooled.

With a spatula, gently fold 1/4 of the meringue mixture into the almond mixture. Continue folding in the meringue until completely incorporated.

Prepare two baking sheets with parchment paper.

Fit a piping bag with a 3/8-inch round tip and fill it with the macaron mixture. Pipe the batter onto the baking sheets. Let them dry at room temperature for 1 hour.

Preheat oven at 275 F.

Bake the macarons for 20 minutes; rotating the baking sheet after 10 minutes for even baking.

In the meantime prepare the buttercream.

In a saucepan bring water and sugar to a boil and cook until the sugar dissolves completely and the mixture is clear, approximately 4 minutes. Then remove from heat.

In the bowl of your electric mixer pour in the egg yolks and crack in one extra egg. Slowly drizzle the hot syrup into the egg yolks while beating. Beat until light and fluffy, about 10 minutes. Add the butter and the lemon zest and continue beating until smooth. Mix in the vanilla. Set aside.

Remove macarons from oven and transfer to a cooling rack; but do not remove them from the parchment paper, yet.

After they have completely cooled, turn half of the caps on their backs and pipe about 1/2 teaspoon of the filling onto them and cover with another cap.

Once all of your macarons are assembled, put them in an airtight container, in the refrigerator and let them rest for another 24 hours before serving.