Preheat oven to 275 ( convection ) or 300 standard.
Using mixer whisk attachment,
whisk egg whites with salt and cream of tartar for about 2 minutes on high.
Sift in 20 g of sugar, whisk to combine.
Add almond extract, vanilla and coloring.
Whisk on high for 7 minutes.
Combine almond flour and 100g sugar in processor.
Process for about 2 minutes.
When whites are stiff but not dry, sift in almond/sugar mixture.
Fold about 30 times until smooth but not runny.
Over-mix and your macaroons will be flat and have no foot,
under mix and they will not be smooth on top.
Pipe batter in 1-1/2 circles on silicone baking sheet ( or parchment ).
Rap completed tray firmly on counter to release bubbles (this prevents cracking).
Let dry 15-30 minutes until tops are just slightly sticky.
Bake for 7 minutes.
Check if one comes off the tray fairly cleanly, if not bake for a little longer (make sure you are using NON-stick baking paper or they will stick).

After cooling, pipe or spread any type of filling on bottom of one cookie and top with another.