1/4 cup freeze dried blueberries, blended into a powder
For the filling:
½ cup unsalted butter, softened
1 ½ cups powdered sugar
2 tbsp lemon zest
1 tbsp milk
Instructions
Place the freeze dried blueberries in a coffee grinder and pulse until finely ground.
Sift the almond flour, powdered sugar and blueberry powder through a fine-mesh sieve into a large bowl and set aside.
In the bowl of a stand mixer fitted with the whisk attachment add the egg whites and cream of tartar.
Beat on low speed.
When the egg whites start begin to increase in volume, gradually add the granulated sugar until fully incorporated.
Add the food coloring and whisk the egg whites until sift peaks form.
Fold in the almond flour mixture one third at a time with a spatula.
Continue folding and turning, scraping down the bowl until it flows like thick lava, about 2 minutes.
Transfer the batter to a pastry bag fitted with a 1/4-inch round tip.
Line the baking sheet with silicon mat or parchment paper.
Pipe the macarons on the prepared baking sheet in 1-inch circles, spacing at least 1-inch apart.
Firmly tap the baking sheet a few times against the counter to release any air bubbles.
Let the macarons sit on the counter for 40-60 minutes until dry to the touch.
Preheat oven to 300˚F.
Bake the macarons for 15-17 minutes or until the feet are well-risen.
Remove from the oven and allow to cool completely. Set aside.
To make the lemon buttercream, in the bowl of a stand mixer fitted with the paddle attachment beat the softened butter, powdered sugar, milk and lemon zest, scraping bowl occasionally, until smooth and creamy about 3-5 minutes.
Pipe the lemon buttercream onto the back of half the shells.
Form a sandwich and repeat.
Macarons should be aged in the fridge for 1-3 days for best results.