Blast almond meal with a food processor or blender until you get a very fine grain (if using almond flour, skip this step)
Add icing sugar, salt and cocoa powder to the almond flour on the food processor or blender and pulse until thoroughly combined. Set aside.
Whip the eggs with cream of tartar until starts to foam
Continue to whip the egg whites adding granulated sugar bit by bit until glossy stiff peaks form
Fold in the almond flour and mix with a spatula until smooth, sticky and glossy
Transfer batter to the piping bag, pipe the cookies onto the baking sheet
Gently tap the bottom of the baking sheets on your counter to rid any large air bubbles
Allow cookies to dry out at room temperature for about 1 hour
Bake in middle rack in a preheated oven at 160°C for 10-12 minutes, rotate half way if necessary
Allow to cool completely before assembling