Line two baking trays with baking paper and use a pencil (bold) to draw circles of 4 to 5 cm in diameter on them, slightly apart. Draw 32 circles for 16 macarons. Then turn the baking paper over (if you drew in bold you should see the circles shining through the paper).
Put the powdered sugar and almond powder through a sieve into a mixing bowl. Mix everything well so that there are no lumps left.
Beat the egg whites with your hand mixer until they are frothy. Then gradually add the granulated sugar and continue beating until you have a nice shiny meringue.
Gently put 1/3 of the meringue into the sugar and almond mixture. Then 'fold' the rest of the meringue into the mixture with the spatula. Make sure that all dry ingredients are nicely incorporated.
Place a smooth piping nozzle (Ø 5 mm) in your piping bag and spoon the batter into it. Hold your piping bag directly over each circle you've drawn and pipe from the center to the edge.
Let the macarons crust for half an hour to an hour by leaving them like that.
Preheat your oven to 140° C and bake the shells for about 20 minutes. Baking time depends on the size of your shells, so keep an eye on them while in the oven.
Let the macarons cool.