Recipe

280 g icing sugar
160 g almond flour
3 large egg whites
50 g sugar
1/2 teaspoon cream of tartar
1 teaspoons blackberry extract. 👉🏻Sieve the icing sugar and ground almonds into a large mixing bowl and regrind mixture., sift once more and discard any larger pieces. Set aside.
In a bowl, whip the egg whites with electric mixer add cream of tartar.
And gradually add the plain sugar until obtaining a thick merengue.
Add the remaining sugar. And add the Blackberry extract . 
Add a one third of sifted of the icing sugar n almond flour and stir gently with a spatula from top to the bottom. 
Repeat until the batter becomes shiny and reaches the consistency of slow moving lava. 
Pour part of the mix to a pastry bag. Pipe a small dollop of batter onto corners of baking sheet. And lay the parchment over. 
Using both hands to hold the pastry bag, pipe batter by placing the tip about 1/2 inch above the parchment at a 45' angle perpendicular to the pan, directly in the center of the first stenciled circle and fill. When the circle is filled stop squeezing.
Dry the batter at room temperature until a firm skin forms on the macaron.
Preheat the oven to 300F