On a large baking tray, place the printed template or if you use a template silpat use that. Cover the template with parchment paper. Tape the edges so the template does not move.
Sift the dry ingredients (gingerbread spice, almond flour and icing sugar) together twice.
In a clean bowl (dried and cleaned with lemon juice or vinegar) add the egg whites and cream of tartar. Using a hand mixer or stand mixer fitted with a whisk attachment, whisk the eggs on high speed until soft peaks are formed.
Bring the speed to low-medium, add the caster sugar in small batches. Whisk on medium high until stiff peaks are formed.
You can either check by rubbing the mixture between your finger tips, the mixture should be smooth if sugar is dissolved.
Remove the bowl from the stand mixer, add 1/3 of the dry mixture into the stiff egg whites. Fold the mixture using a spatula.
The mixture is folded to deflate the air in the batter, while folding scrape along the sides of the bowl bringing it to the middle.
Add the rest of the dry ingredients and repeat. This step is "macaronage" and its one of the most important steps. See notes for link to Mimi's page ( I havent seen any other site explaining it so well).
The batter is ready when you can it has a lava like consistency or you can make a 8 pattern with it as a smooth flow.
Using a round tip, add the mixture into a piping bag.
Press gently and let the mixture fall into the template. If the batter is mixed right, you can see the tips from the piping gently settling in.
Remove the template, tap the baking sheet on the kitchen counter few times. This helps in escaping the air bubbles in the batter.
Let it sit in room temperature for an hour to when the shell is dried out and this is called forming of the skin.
The skin is formed, when the batter does not stick to your fingers when you touch it. Please make sure the humidity is less as it makes it harder for the skin to form.
Preheat the oven to 160 degrees celsius or 320F for 12-14 minutes.
Slightly peel the parchment sheet from the bottom of the macaron, if the macaron peels off easily then it is baked.
Once they are baked, let it cool on a cooling rack.