Toast the coconut flakes in a large pan without adding any fat until light yellow. Pour onto a plate and let cool down.
Beat the egg whites with a hand mixer until stiff. Briefly mix in the sugar, cinnamon and (if desired) the bitter almond oil. Carefully fold the cooled coconut flakes into the egg white mixture with a spatula.
Place 2 teaspoons of the mixture on a baking sheet lined with baking paper.
Preheat the oven, top / bottom heat 140 °, hot air 120 °. Baking time approx. 25 minutes.
Remove the macaroons from the baking sheet with the parchment paper and let them cool.