Heat oven to 180C/fan 160C/gas 4 and line a baking tray with parchment paper.
In a large bowl, mix together the ground almonds, caster sugar and orange zest.
In another medium-size bowl, whisk the egg whites for a few secs until the whites are broken up.
Pour half the egg white into the dry ingredients and mix until it comes together – you may need to add more egg white; it should be quite a soft and sticky mixture.
Roll the soft dough into a large sausage, then divide it into 18 parts (each about 1 heaped teaspoon).
Roll each piece in the flaked almonds sprinkled on a plate and, with your hands, form into simple crescent shapes.
Place on the baking tray and cook for 13-18 mins until golden.
Remove from the oven and cool on a wire rack.
This recipe is by Rachel Allen and is reprinted with the permission of the BBC Lifestyle channel.